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Appendix I

1. etii daba den 168 4 7 AN Version E reales 168 4 8 Q erying WERE Se 168 49 Mul ple ATOM PVT generati n engen 168 5 COMPRESSION OPTIONS POR ATOM RNX OBSERVABLES sense 170 ATOM UTILITIES nein ie ie 171 Appendix A PASHR transport decoding Sample ee 172 Appendix B ATOM message decodine ei 173 Appendix C Decomposition for ATOM RNX observables u a ee er 176 CI General principles to decompose original observables usa ee 176 C 2 Explicit algorithm to restore original observables una ee 178 Appendix D Decimation for ATOM RNX observables u een nenn 187 Appendix E Data identifiers for ATOM RINK 188 E l Satellitemask e ee 188 MEE eo ec ee EE 188 E3 Capability making ee 190 lE Uoc CN E E 190 BS Example of building Satelite Signal and Cell Ma tee ea 191 EG Example of interpreting Satellite Signal and Cell Masks nn een ca M Fa PRU MP 193 Appendix F Throughput figures Tor ATOM RNX observables ee 196 Appendix G Miscellan
2. Y coordinate 38 int38 52 Ditto Ditto Ditto DF026 Z coordinate 38 int38 90 Ditto Ditto Ditto DF027 Total 128 Notes Atthe moment reserved bits are planned to be used in future for the following standardized 3 indicators VRS indicator DF141 1 bit Reference Oscillator Indicator DF142 1 bit Clock Steering Indicator DF411 2 bits External Clock Indicator DF412 2 bits e Motion flag must be interpreted as following If it indicates moving receiver then processing equipment must consider this and each next if it does not contain reference position data epoch of RNX observables as corresponding to moving receiver It is recommended to generate reference position each observation epoch If motion flag indicates static receiver then processing equipment should consider this and each next if it does not contain reference position data epoch of RNX observables as corresponding to static receiver It is sufficient to generate reference position with admissible decimation e g in 10 30 times compared to RNX observables Decoding equipment must not make any a priori assumptions regarding time intervals between reference positions epochs and changes in reported motion flag from epoch to epoch e tis not possible to indicate reference position quality flag in all the cases that is why very often the default quality flag is unknown Table 3 8 5 b Compact reference position clarification data Data it
3. Total Notes Unlike with other ATOM groups the station ID is not provided in the ATM PVT header But it can be available in extended form four Characters in the ATM PVT MIS block ATOM version switch 1 or 2 affects the content of SVS block only see below The receiver usually features a number of basic PVT sub engines each of them or some of their combinations can deliver user position at given epoch Field AF002 provides the information what PVT sub engine s configuration delivered position results In general field AF002 can change with epochs depending on environmental conditions and or the differential data link status E g when data link stops for a long time initially reported AF002 9 can transit to AF002 6 is generic message and in some specific cases user can request a number of different PVT style messages So with multiple ATM PVT messages referring to given time tag end user must understand which messages corresponds to serial commands he she issued to request them Field AF020 allows user to match each decoded message with corresponding PASHS ATM command request It is supposed that up to more than one antenna connector can serve a particular GNSS board so antenna ID AF019 is provided For each h w configuration each antenna connector can have its own unique index For MB500 GNSS board only antenna connector 1 is available For MB100 GNSS board two antennae connecto
4. Start Message Data from Data from Data from Reference End Transport Header first GNSS second GNSS 7 Nth GNSS Position Transport 3 bytes 10 bytes 3 bytes ug GNSS Header a 0 o a Observable Capability Cell Satellite Signal Position Clarification Velocity and Mask Mask Mask Data Data parameters clock Specifies data Data specific for current type of signal fine pseudorange Velocity and receiver clock presentation T carrier phase SNR Position and attributes Antenna height or Contains information about Rough satellite data rough extended time tracked satellites pseudorange rough Doppler Contains information about azimuth elevation types of tracked signals Figure 3 8a Organization of RNX message 3 8 1 Output Logic Message binary size How to request Permissible intervals x sec See also Message structure and header on time depends on message content PASHS ATM RNX lt Port Name gt ON x 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min PASHR MPC PASHR PBN RTCM 3 MT 1001 1006 1009 1012 RTCM 2 MT 18 19 24 RTCM 3 MSM Table 3 8 1 a Message structure and header content ashtech Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 Bit6 8 Set to 000000 Message Length 10 uint10 14
5. data on port and port Z virtual port with different intervals 600 and 300 seconds respectively PASHS ATM NAV A ON 600 SEPH PASHS ATM NAV Z ON 300 amp EPH Enable ATOM DAT raw navigation data for all tracked GNSS data on port C PASHS ATM DAT C ON amp FRM The following rules should be known when applying customization to sub messages sub blocks Requesting a sub message without specifying its period will result in a sub message output with the default period e Requesting several sub messages through a single string that contains at least one syntax error will result in no setting applied at all Requesting several sub messages with different periods will result in each of the sub messages output with its specific period e Disabling all previously enabled sub messages will put an end to the generation of the complete group message User must also realize the following GNSS receiver can operate with different internal update rate which is controlled by receiver options and POP setting Depending on internal update rate not all the output rates are permissible E g with 5 Hz internal update rate one can utilize only fast intervals 0 2 and 1 sec but not 0 5 0 1 and 0 05 sec 4 3 Using the Extended Serial Interface for Observables Scenario Customization Unlike the other ATOM messages RNX has an extra feature it can generate the same observation data in different forms thereby allowing some
6. Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes Set to 12 for this message MESSAGE HEADER Message number 12 uintl2 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 4 is reserved for ATOM ATR message Version 3 uint3 40 0 7 ATOM version number set to 1 ashtech Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which message follows For ATR message type 9 uint9 55 0 511 this message set to 25 MESSAGE DATA Reserved 3 bit3 Temperature 11 intl 0 1 degree 102 3 Value 102 4 means invalid Pressure 17 uintl7 0 01 mb 0 1310 71 Value 1310 71 means invalid Relative humidity 10 uintl1O 0 1 0 102 23 Value 102 3 means invalid Reserved 15 bit15 Set to 0 0 END TRANSPORT CRC 24 uint24 24 bit Cyclic Redundancy Check CRC Total 142 3 5 9 ATOM ATR Message External Sensors Data Additional Header 3 5 10 ATOM ATR Message Receiver Installed Options 3 5 11 ATOM ATR Message Receiver Configuration 3 5 12 ATR Message GLONASS Code Phase Bias This message generates so called GLONASS Code Phase bias values for up to all FDMA GLONASS observations It is extended copy of RTCM 3 1230 F
7. ITRF epoch year 6 uint6 0 0 63 pe Antenna height 16 uint16 6 0 0001 m 0 6 5535 Value 6 5535 means 6 5535 Total 22 Table 3 8 5 e Clarification data for reference position clarifier 1 Data item Bits Data type Offset Scale Range Comments DF Number REFERENCE POSITION CLARIFICATIONS DATA See DF054 GPS UTC time offset 6 uint6 0 1 sec 0 63 63 means undefined or invalid For GPS wn modulo 4095 cycle The number of GNSS For BDS wn modulo 4095 cycle cz 12 uint12 6 0 4095 y For GLO day number of 4 year period DF129 ushtech 4095 means underfined or invalid Receiver time status 4 uint4 18 0 8 See Appendix G AF010 Total 27 Note e Official RTCM field DF021 is actually reserved for the ITRF epoch year but not claimed as usable ATOM follows the same strategy Once RTCM claims that DF021 is usable ATOM will use it as well e number of GNSS time cycles refers to GPS Week number 0 4095 0 starts midnight January5 January 6 1980 rolls from 4095 to 0 if GPS is primary system e number of GNSS time cycles refers to GLONASS day number 1 1461 day 1 corresponds to January 1 1996 rolls from 1461 to 1 zero means unknown day values 1462 4095 are not used if GLONAS is primary system Receiver time status refers to time scale of primary GNSS system ashtech This section describes the extended observation data The gen
8. Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes MESSAGE HEADER ashtech Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 NAV message type 9 uint9 55 0 511 Specifies which NAV message follows MESSAGE DATA Navigation content See sub sections below END TRANSPORT CRC 24 uint24 24 bit Cyclic Redundancy Check CRC Total Supported NAV messages are presented in Table 3 6 b Table 3 6 b Supported NAV messages NAV message ASCII identifier Attribute description Comments Counterpart type GPS ephemeris from LICA Copy of standardized message i signal data RTCM 3 type 1019 re GLO ephemeris from LICA Copy of standardized message 2 signal data RTCM 3 type 1020 a 3 SBAS ephemeris from LICA of SNW message but in RTCM 3 not yet signal data compact presentation standardized 4 EPH GAL ephemeris I NAV Modified copy of RTCM 3 type RTCM 3 MT 1046 not yet from E1b E5b signal data 1046 draft standardized 5 EPH QZSS ephemeris from LICA
9. Message Galileo Almanac This message contains GAL almanac data for a given GAL satellite extracted from I NAV signal For detailed information about GALILEO almanac data please refer to the GALILEO OS SIS ICD September 2010 document Output Logic on time on change on new Message Binary size 37 bytes 296 bits How to request PASHS ATM NAV Port Name ON x amp ALM Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also Table 3 6 10 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes Set to 31 for this message shtech MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which NAV message follows For NAV message type 9 uint9 55 0 511 ilis message set to 14 MESSAGE DATA The GALILEO 5 parameter is coded See DF252 with 6 bits However the max constellation which can be SVPRN 6 t6 64 1 36 ps bos accommodated withi
10. ashtech An 16 int16 208 2 Mean anomaly correction semicircles sec DF087 m0 32 int32 224 73 Mean anomaly at reference time DF088 semicircles Cuc 16 int16 256 2 Harmonic correction term radians DF089 E 32 uint32 272 a Eccentricity DF090 Cus 16 int16 304 a Harmonic correction term radians DF091 A 32 uint32 320 pe Square root of semi major axis meters DF092 Toe 16 uintl6 352 16 Reference ephemeris time DF093 Cic 16 int16 368 2 Harmonic correction term radians DF094 c0 32 int32 384 ge Longitude of ascending node semicircles DF095 Cis 16 int16 416 ge Harmonic correction term radians DF096 10 32 int32 432 23 Inclination angle semicircles DF097 Crc 16 int16 464 Harmonic correction term meters DF098 o 32 int32 480 27 Argument of perigee semicircles DF099 dot 24 int24 512 m Rate of right ascension semicircles sec DF100 8 int8 536 gal Group delay sec DF101 Health 6 uint6 544 Satellite health DF102 nm i w s d Fit Interval 1 bitl 551 Curve fit interval DF137 END TRANSPORT CRC 24 uint24 552 24 bit Cyclic Redundancy Check CRC Total 576 Notes See Appendix B for decoding sample ashtech 3 6 ATOM NAV Message GLONASS Ephemeris This message contains GLONASS ephemeris data for a given GLONASS satellite For detailed information about GLONASS ephemeris data please refer to the GLONASS ICD ver 5 do
11. ashtech Cis 16 416 FF E4 9 5 215406E 008 i0 32 432 28 2218 45 2 3 135405E 001 Cre 16 464 19 F5 2 2 076563E 002 o 32 480 76 70 BA D7 PER 9 253152E 001 dot 24 512 27 a 2 469392E 009 8 536 F8 2 3 725290E 009 Health 6 544 00 0 L2 P data flag 1 550 01 1 Fit Interval 1 551 00 0 END TRANSPORT CRC 24 552 D8 82 21 Total 576 ashtech shtech Appendix C Decomposition for ATOM RNX observables This Appendix describes in detail the principles of breaking down ATOM RNX observables thus providing a bridge between the different choices for the OPT optimization option see section 5 3 and the corresponding ATOM presentations see sections 3 8 and 3 9 Cl General principles to decompose original observables With proper receiver design basic observables pseudo range and carrier phase always appear as being controlled by the same receiver clock As a result the dynamic of all pseudo ranges and carrier phases corresponding to the same satellite is almost the same Only ionosphere divergence receiver biases and some other negligible factors can cause the divergence of one observable against another This fact is used when generating compact observations It was initially introduced in the Trimble CMR format and later appeared as a primary concept in standardized RTCM 3 observation messages Being quite attractive at that time it has now become some
12. shtech 15 2009 Few style changes done towards releasing the Manual for end user Code quality flag meaning in ATM RNX SCN 0 is extended Message BIS is transferred to new STA group under the name BLA Message SNS Sensors data is added to ATR group Field AF006 is clarified Some style corrections added User cases of different RNX scenarios are clarified in section 5 Magellan Pro changed to Ashtech 1 09 January 15 2010 PVT solution type field AF009 introduced 1 10 February 10 2010 Style changes from Patrice done towards releasing 1 09 as user Manual Description of ATOM BAS temporary removed but section header is still kept The above changes are accepted for more clear view of the changes which follow More clarifications added about generated position in section 2 4 and 2 5 ATM ATR SNS corrected Invalid states for position generated in PVT MES and RNX are introduced Receiver time status in ATM RNX position block Field AF010 introduced Style corrections March 10 2010 Wn field in ALM is clarified Mentioning of GPRRE message removed Misprint in time tag description fixed Style corrections 1 12 April 15 2010 Invalid values for some RNX fields clarified STA message clarified AFO006 field clarified 1 13 May 31 2010 ATM ATR SNS message modified Field AF011 introduced in ATM RNX header Section 2 4 modified Block ATM PVT LDP is added B
13. 2 0 Smoothed Doppler Doppler quality 1 5 0 1 1 Not smoothed Doppler 0 no cycle slip suspected Same as MPC EM f pt 1 cycle slip is possible warning bit 6 0 continuous carrier tracking Same as MPC EOS on 1 Bitl d 1 1oss of lock occurred warning bit 7 Reserved 6 Bit6 8 0 63 See Appendix G AF005 Total 14 Notes Invalid smoothing residuals do not obligatory mean invalid value of corresponding pseudo range The bits in the MPC warning byte are counted from 0 to 7 MPC bit 5 Z tracking is not reflected here but it is reflected in Signal Mask signals 1W and 2 bits 0 1 are not reflected here but they are reflected in Satellite status field in Extended Satellite data A special state for fractional carrier bias was reserved to allow a not fixable carrier to be generated applicable to carriers from some consumer receivers such as SiRF This state indicates that the carrier can have an arbitrary float bias during its continuous tracking Because of that its Double Difference ambiguity can never be fixed to integers In general transitions between states of fractional carrier bias field are accompanied by carrier cycle slip and loss of lock indicators if carrier bias has been actually changed when resolving polarity or suspected to be changed when losing data synchronizations However if resolved polarity is correct and no half a cycle correction introduced then cycle sli
14. Attitude supplementary data ROT 13 Baseline supplementary data BDS 19 Original datum clarification CDC Depends on message content Local datum position LDP Depends on message content Local map projection LMP Depends on message content Satellites status SVS Depends on tracking status ATOM PVT allows outputting receiver position tagged to different points including L1 antenna phase center antenna reference point or ground mark Corresponding identifier is provided inside ATOM PVT body Antenna height the height of antenna reference point above ground mark is usually provided so user can re compute position tagging as he she wants Having requested antenna name user is also able to make ease transformations between L1 antenna phase center and antenna reference point positions Block COO of ATOM PVT message outputs position referring to some datum This datum can be indicated as default which is defined by datum of broadcast ephemeris i e 16505 realization of ITRF2005 on current epoch if GPS is primary datum reference position is tagged to for RTK and DGNSS only It must be noted that often it is not known a priori what the datum of reference position is In this case block MIS of ATOM PVT indicates default datum which is actually correct only if reference position is tagged to the same datum as used ephemeris are If it is not so then default actually means unknown for RTK and or DGNSS positions
15. Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Depends on message content Block ID 4 uint4 8 0 15 Setto 15 Sub Block Id 8 uint8 12 0 255 Set to 2 Semi major axis of 24 uint24 20 0 001 0 16 777 215 Add it to 637000 to get final value See DF166 datum ellipsoid 25 uint25 44 0 001 0 33 554431 Add it to 635000 to get final value See DF167 datum ellipsoid Reserved 16 bit16 69 Set to 0 0 The source of 0 unknown source Soda 3 uint3 85 0 7 1 RTCM 3 clarification 2 7 reserved Descriptor counter N 8 uint8 88 0 255 Number of characters in local datum See DF143 descriptor field Local datum descriptor 8 N char N 96 Alphanumeric characters to clarify used See DF144 local datum name ashtech Total Notes These data allow to know what custom datum name and ellipsoid parameters is for position in COO block and getting latitude longitude and altitude components of Cartesian COO position 3 415 ATOM PVT Message Sub Block Position expressed in local cartographic projection This sub block LMP Local Map Projection is originated by position in COO There is no need to request the LMP block specially each time when COO block is generated and projection parameters corresponding to COO positions are available block LMP is generated If there
16. 13 Residuals tracking usage 1101 Pseudo range Residuals for L1 signal only GPGRS statust Depends on ATM PVT 3 A REY PASHR SAT 14 SVS Sat status a 1110 Satellite tracking usage information GPGSV tracking status SPECIAL BLOCKS 1111 15 0 Reserved 00000000 15 1 LDP Local Datum Depends on 00000001 Position from block COO expressed in local N A Position message user datum ashtech content 152 CDC Custom Datum d E u The name and parameters of the custom N A Clarification datum of position in block content Depends on 00000011 15 3 LMP Local Map 5 Position from block LDP expressed in local GPGMP Projection cartographic projection content 00000100 15 4 15 255 Reserved 11111111 All supported PVT blocks except 15 output general purpose position information which is usually available for each GNSS receiver firmware In future reserved blocks can contain some extra general purpose position data In contrast block 15 Special messages can contain some information specific to particular GNSS receiver firmware The organization of general purpose and special blocks is presented in the tables below Table 3 4 f Presentation of general purpose PVT sub blocks Data item Bits Data type Offset Scale Range Comments DF Number GENERAL PURPOSE SUB BLOCK DATA The size of giv
17. All observables are never compensated for antenna specific biases On the other hand original receiver observations can be matched to the desired virtual antenna name The corresponding physical and virtual antenna names can be provided by ATR messages thus making it possible if needed to restore the observations corresponding to the physical antenna All observables are never compensated for receiver specific biases On the other hand original GLONASS receiver observations can be corrected to the golden Ashtech receiver type to make GLONASS double difference observations unbiased between given and golden receiver The optional reference position which can be generated inside ATOM observation messages is supposed to be referred to proper ITRF epoch year which is usually indicated inside ATOM body Reference position in ATOM RNX can be tagged to different points including L1 phase center antenna reference point and ground mark Usually antenna height the height of antenna reference point above ground mark is provided together with reference position so user can re compute reference point position to ground mark position and vice versa Also antenna name can be requested from receiver to allow transformation between L1 antenna phase center and antenna reference point Reference position in ATOM RNX can be either static e g entered position or can be kinematic moving position receiver computes each epoch Latter case allows u
18. MESSAGE DATA Reserved 12 uint12 64 Set to 0 0 SVPRN 6 uint6 76 1 77 Satellite PRN number starting from 1 SatHl 1 bit 82 Autonomous Satellite Health flag AODC uint5 83 Age of Data Clock URAI 4 uint4 88 User Range Accuracy Index Wn 13 uint13 92 0 1023 Beidou week number toc 17 uint17 105 8 Reference time of clock parameters Bedl 10 int10 122 0 1 Group Delay Differential 10 int10 132 For future Equipment Group Delay Differential 2 a2 11 int11 142 pe Clock correction sec sec a0 24 int24 153 2 Clock correction sec al 22 int22 177 297 Clock correction sec sec AODE 5 uint5 199 Age of Data Ephemeris ashtech Mean motion difference from computed t6 204 2 value semicircles sec E Amplitude of cosine harmonic correction Cuc 18 int18 220 2 term to the argument of latitude radians m0 32 int32 238 y 2 at reference time e 32 uint32 270 ges Eccentricity Cus 18 int18 302 gal Harmonic correction term radians Crc 18 int18 320 2 Harmonic correction term meters Crs 18 int18 338 2 Harmonic correction term meters AU 32 uint32 356 p Square root of semi major axis meters toe 17 uint17 388 8 Reference ephemeris time sec 10 32 int32 405 Inclination angle semicircles Cic 18 int16 437 27 Harmonic correction term radians dot 24 int24 455 gm Rate of right ascension semicircles sec Cis 18 int16 479 2 Harmonic c
19. descriptor counter M field 8 M char M Standard ASCII characters describe receiver DF230 firmware version Serial 8 uint8 Number of characters in serial number field DE231 descriptor counter K Serial number 8 char K Standard ASCII characters describe receiver DF232 serial number END TRANSPORT CRC 24 uint24 24 bit Cyclic Redundancy Check CRC Total 3 5 4 Message User message This message contains readable content users can define at their convenience Output Logic on time Message Binary size depends on message content How to request PASHS ATM ATR lt Port gt Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHS MSG RTCM 3 MT 1029 RTCM 2 MT 16 Table 3 5 4 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes MESSAGE HEADER shtech Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 4 is reserved for ATOM ATR message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Refe
20. 5 25 29 Reserved 30 11 L1C D 31 11 11 32 11 L1C D P SBAS Satellite ID mapping Satellite ID in Satellite Mask Comment DF394 SBAS Satellite PRN 1 120 Original SBAS 2 121 9 40 8 QZSSLISAIF 44 187 45 64 Reserved It can be some BDS in future SBAS Signal ID mapping SignalIDin Frequency Signal GPS signal Comments Notes Signal Mask Band RINEX DF395 code 1 Reserved 2 11 1 3 21 ashtech SignalIDin Frequency Signal GPS signal Comments Notes Signal Mask Band RINEX DF395 code 22 L5 I 51 23 15 Q 5Q 24 L5 X 5X 25 32 Reserved GLONASS Satellite ID mapping Satellite ID in Satellite Mask GLONASS Satellite slot DF394 number 1 1 2 2 24 24 25 64 GLONASS Signal ID mapping Signal ID in Frequency Signal GLONASS Comment Notes Signal Mask Band signal DF395 RINEX code 1 2 Gl C A 1C 3 Gl P 1P 4 7 Reserved 8 G2 C A 2C 9 G2 P 2P 10 32 Reserved GALILEO Satellite ID mapping ashtech Satellite ID in Satellite Mask DF394 50 51 52 53 64 GALILEO Satellite PRN 50 GIOVE A GIOVE B Reserved GALILEO Signal ID mapping Signal ID in Signal Frequency Signal GALILEO Comments Notes Mask DF395 Band signal RINEX code 1 2 El C n
21. PIS block is removed from PVT message 2 03 Mar 31 2011 Few misprints corrected Number 0 is claimed to be reserved for ATOM DBG group Bit mask definitions clarified in section 3 2 Some clarifications added to Section 4 Mentioning fields AF001 and AF004 removed Section G 4 added Message DLS modified 2 04 Apr 29 2011 Exact definition for Satellite Signal and Cell mask is added with reference to RTCM 3 MSM fields DF394 DF395 DF396 Message ATM ATR SAH is added ashtech Message ATM STA AST is added Clarifications are given for AF002 and AF009 in ATM PVT header 2 05 May 31 2011 New FST group created with single message PIS New STA message SSC created New ATM PVT sub block ROT created New ATM DAT INT message created A number of clarifications are given for ATM STA messages Some corrections additions for ATM RNX to match latest MSM changes 2 06 June 30 2011 ATR CSD message is removed as not needed anymore Appendix C is extended with RNX data restoration algorithm Appendix G is extended with description of data link effective ATM RNX scenario for moving base RTK New fields or reserved positions are introduced for ATM PVT Section 6 ATOM Utilities updated Signal Satellite and Cell masks description updated Detailed clarification of Signals and Satellite IDs is provided for GPS other GNSS will be updated later 2 07 July 31 2011 Section
22. specific term should be based on the following formula Full Specific N resolution where N is the integer to be determined The resolution is 655 36 meters for pseudo ranges and 4096 cycles for carrier phases The integer value N can be found with the help of rough range if it is provided by ATOM or can be restored if rough range is not provided by ATOM using the knowledge of the reference position and the availability of ephemeris data See section C 2 for additional details ashtech Some applications can work with the fractional carrier phase only That is why ATOM allows such an option sending only the fractional carrier phase Also there is a possibility to restore the full carrier phase from the fractional carrier However this is only possible if it is known a priori that the receiver generating the fractional carrier is a static receiver The table below to be compared to the 6 table in section 5 3 shows which components of the original observables are generated depending on the choice made for the OPT optimization option The generated rough_range can either be full rough_range or rough_range modulo ms The generation of the number of integer ms in rough_range is not controlled by the OPT setting In contrast this value can be generated or not generated depending on the choice made for the SCN option Compact Full NoL 0 Not any data 1 Fine pseudo range 2 Fine pseudo range Rough range same for
23. 0 1 Setto 0 Receiver clock offset 30 int30 228 0 001 m 536870 911 m 536870 912 if not defined or invalid ashtech Receiver clock drift 22 int22 258 0 001 m s 2097 152 m s 2097 152 if not defined or invalid Total 280 Notes ashtech Receiver clock offset and Receiver clock drift refer to the original receiver observables the clock of which is typically kept within 1 ms By contrast observables reported in ATOM are clock steered The availability of the receiver clock offset and clock drift allows 3 party users to restore original not steered receiver observables Reported receiver clock offset and drifts refers to the time scale of primary GNSS system specified in RNX message header This value is used for clock steering in all GNSS observables e t must be noted that clock steering procedure affects not only observables but also reference position when this position corresponds to very high dynamic receiver In this case user who desires to return to not steered data will have not only to correct original observables but also original reference position Table 3 8 5 d Clarification data for reference position clarifier 0 Data item Bits Data type Offset Scale Range Comments DF Number REFERENCE POSITION CLARIFICATIONS DATA
24. 1000 MCA 108 12 2 1296 MPC ATOM RNX SCN 0 829 425 561 Fullest presentation RNX SCN 4 317 205 193 Standard presentation RTCM 3 338 MT 1004 10012 214 MT 1002 1010 202 MT 1004 RTCM scenarios matched to ATOM SCN 4 ATOM SCN 100 159 140 98 Compact presentation ATOM SCN 101 86 75 70 Super compact presentation only applicable to static receivers The worst case Usually in normal conditions 4 bytes can be subtracted for each system shtech Notes throughput for ATOM is the same for the same scenario used e Scenario 100 stands for the triplet SPE 3 DEC 5 and OPT 7 Scenario 101 stands for the triplet SPE 3 DEC 5 and OPT 4 SPE 3 refers to sending L1 and L2 one signal per band pseudo range and carrier phase data modulo 1 ms and not sending SNR DEC 5 refers to decimating all the data in 5 times compared to L1 carrier data OPT 7 refers to compact pseudo range and full carrier phase OPT 4 refers to compact pseudo range and compact carrier phase These figures show that Using message in its full presentation SCN 0 instead of legacy MPC MCA data can reduce size by 2 3 times without loss of any legacy fields e Standard RNX scenario SCN 4 shows approximately the same throughput as their RTCM 3 counterparts e Applying admissible i e not leading to performance degradation optimization scenarios allows dramatic reduction
25. 1048 575 1048 576 if not defined or invalid 0 Ellipsoidal height Height Indicator 2 uint2 181 0 3 1 Geoid Quasi Geoid or Local height See DF 151 2 3 reserved Reserved 20 bit20 183 Set to 0 0 er 0 unknown source Utilized transformation 3 uint3 203 0 7 1 RTCM 3 source 2 7 reserved Source clarification 10 bit10 206 1 2 Undefined otherwise Number of characters in local datum See DF145 The Target Name descriptor field defines number of Counter en characters bytes to follow in Target Name Alphanumeric characters to clarify used See DF146 local datum name If available the Name of Target EPSG identification code for the CRS Coordinate System 1 1 oordinate S ystem g N char N 224 has to be used Otherwise service providers should try to introduce unknown CRS s into the EPSG database or could use other reasonable names Total Notes See NMEA GPGMP message description for additional details 3 5 ashtech Messages from the ATR ATRibutes group contain different additional and service information such as antenna and receiver description antenna offset parameters against ground mark Some messages have fixed length some others have variable length All these messages can be requested independently of each other Only one ATR message can be output over any given 1 interval The set of default ATOM ATR messages with default
26. 15 2 7Q 16 32 Reserved Appendix J Example of ATOM masking table for a particular product
27. Many users can be interested in getting position in some specific local datum and or projection ATOM PVT applies the ideology that block COO always reports originally computed position indicated as default or custom in block MIS while extra block s can output block LDP Local Datum Position and or LMP Local Map Projection See complete ATOM PVT description for detailed formats is open to adding more sub blocks in future It should also be noted that Ashtech PVT data are usually output under the same header possibly with a unique update rate for each block i e inside a single ATOM PVT transmission On the other hand each particular sub block e g COO or SVS can be output under its own header i e using a separate transmission In the latter case the multiple message bit in the ATOM PVT header is set accordingly to allow the receiving entity to compile complete position epoch data from different transmissions The two diagrams below show different transmission strategies applicable to ATOM PVT messages 3 sub blocks are given as examples In some cases e g when Network provider delivers additional information about the source datum local datum and map projections extra ATM PVT blocks can supplement original position generated in block COO In general these extra blocks clarify e The name of the datum COO position is expressed in CDC block COO coordinates expressed in a local datum
28. SF4 1 bit 103 Ionospheric disturbance Flag for region 4 SES 1 bitl 104 Ionospheric disturbance Flag for region 5 AO 32 int32 105 m Constant terms of polynomial s Al 24 int24 137 2 First order terms of polynomial s s AtLS 8 int8 161 GAL UTC differences at reference time Tot 8 uint8 169 3600 Reference time for UTC data Wnt 8 uint8 177 0 255 UTC reference week number WnLSF 8 uint8 185 0 255 when leap second became DN 3 uint3 193 07 2 7 when 1 second became ALLSE 8 int 196 2 between and UTC after ashtech 16 int16 204 235 Constant terms of polynomial for GAL gt GPS AIG 12 int12 220 25 pis terms of polynomial for GAL TotG 8 uint8 232 3600 Reference time for GAL gt GPS WntG 6 uint6 240 0 255 reference week number for GAL gt GPS reserved 2 uint2 246 END TRANSPORT CRC 24 uint24 248 24 bit Cyclic Redundancy Check Total 272 3 6 16 Message QZS and time shift parameters This message contains 0755 ionosphere and time shift parameters For detailed information about these parameters please refer to the IS QZSS_13 E document Output Logic on time on change on new Message Binary size 32 bytes 256 bits How to request PASHS ATM NAV lt Port Name gt ON x amp GIT Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR I
29. See Section 3 8 2 and Tables 3 8 2 b and c H 3 Extended data resolution in ATOM RNX GNSS observables block Extended resolution is supported for ATOM v 2 but it is not supported for ATOM v 1 See shtech e Section 3 8 2 and Table 3 8 2 a e Section 3 8 4 and Table 3 8 4 a b e Section 3 8 6 and Table 3 8 6 b c shtech Appendix I Satellite Signal and Cell Masks These three masks are so important so we describe them in separate section Their description follows ATOM v 2 while ATOM v 1 uses truncated versions of Satellite 40 bits and Signal 24 bits mask These masks are used in ATM RNX message and with smallest modification for Cell Mask in ATM PVT message They are twins of standardized RTCM 3 fields DF394 DF395 and DF396 used for generation so called Multiple Signal Messages MSM The table below provides complete description The sequence of bits which specifies those GNSS satellites for which there is available data in this message The Most Significant Bit msb or the first encoded bit corresponds to GNSS satellite with ID 1 the second bit corresponds to GNSS satellite with ID 2 etc And the Least Significant Bit Isb or the last ecoded bit corresponds to GNSS satellite with ID 64 Exact mapping of actual GNSS satellites PRNs for GPS slot number for GLONASS etc to satellite mask IDs is specific for each GNSS see corresponding tables in MSM description for each particular GNSS
30. Site occupation information This message contains information about site occupation It is copied in EVT group see section 3 10 Output Logic on new on change Message Binary size depends on message content How to request N A Permissible intervals x sec N A See also N A Table 3 5 6 0 Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT ashtech Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 4 is reserved for ATOM ATR message Version 3 uint3 40 0 7 version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which ATR message follows For ATR message type 9 uint9 55 0 511 this message set to 23 MESSAGE DATA Time tag 21 bil GPS time tag See Time Tag description for PVT message 0 static 1 quasi static Occupation type 3 bit3 0 7 2 dynamic 3 event 4 Kinematic bar Occupation event 1 bitl 0 1 1 end Reserved 7 bit7 0 Set to 0000000 Occupation name 8 uint8 0 255 N umber of characters in occupation name counter N field Occupation name 8 N char N Standard ASCII chara
31. block COO coordinates expressed in local map projection LMP block Sometimes a clarification about reference position datum is known a priori e g source datum name from so called RTCM 3 coordinate transformation messages In this case block MIS of ATOM PVT will indicate custom datum and additional ATOM PVT block CDC custom datum clarification which clarifies the name and parameters of this custom datum 18 generated ashtech Message COO Data ERR Data SVS Data Transport Header Transport One transport frame several information blocks inside Message COO Data End Message ERR Data End Several messages with their Header Transport own transport frames Message SVS Data End Header Transport More words must be said about multiple ATOM PVT output In the most of user cases complete GNSS solution corresponds to single receiver antenna single dedicated correcting data stream etc In this case all sub blocks inside ATOM PVT are tagged to this unique GNSS solution At the same time Ashtech GNSS platform can deliver to end user advanced GNSS solution which includes more than single antenna and correcting source For example Ashtech supports RTK heading solution or RTK Full altitude solution where obviously more Start Transport Start Transport Start Transport ashtech than single antenna and corresponding corrections observations are used For such advanced GNSS solutions user can be suppli
32. 00 FF F1 E9 54 2A FC 95 2A 94 14 A6 FO 58 FC 8B 05 69 B3 06 13 E2 Al C9 32 72 42 00 59 29 D9 58 FF 4 28 22 18 45 19 F5 76 70 BA D7 FF AB 27 F8 02 Message Data 61 bytes D8 82 21 End Transport 3 bytes Resulting ASCII presentation Data item Bits Offset Binary HEX Scale ASCII Decimal START TRANSPORT Transport Preamble 8 0 D3 211 Reserved 6 8 00 0 Message Length 10 14 42 66 MESSAGE HEADER Message number 12 24 FF 4095 Message sub number 4 36 05 5 Version 3 40 01 1 Reference station ID 12 43 00 IF 31 message type 9 55 00 01 1 MESSAGE DATA m message 12 64 03 FB 1019 SVPRN 6 76 08 8 Wn 10 82 01 D9 in 1497 Accuracy 4 92 00 0 Code on L2 2 96 00 0 Idot 14 98 03 03 x 8 765255E 011 Iode 8 112 2 42 16 120 72 42 16 468000 af2 8 136 00 z 0 000000E 000 afl 16 144 FFFI 27 1 705303E 012 22 160 68 15 2 1 706979E 004 Iodc 10 182 2A 42 Crs 16 192 FC 95 g 2 734375E 001 An 16 208 2A 94 1 239187E 009 m0 32 224 14 A6 F0 58 23 1 613446 001 16 256 8 27 1 648441 006 32 272 05 69 06 2 1 057205E 002 Cus 16 304 13 E2 9 480864E 006 32 320 AI 0D C9 32 2 5 153723E 003 Toe 16 352 72 42 16 468000 Cic 16 368 00 59 2 1 657754 007 o0 32 384 29 D9 CF 58 2 3 269595 001
33. 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also Table 3 4 13 a Sub Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Depends on block content Block ID 4 uint4 8 0 15 Set to 15 Sub Block Id 8 uint8 12 0 255 Set to 1 13743895 3472m if not defined X coordinate 38 int38 20 0 1 mm 13743895 3471 invalid 13743895 3472m if not defined Y coordinate 38 int38 58 0 1 mm 13743895 3471m invalid 13743895 3472m if not defined 7 coordinate 38 int38 96 0 1 mm 13743895 3471m invalid Latitude 38 int38 134 1 9 deg 90 deg Value out ot interval 20 20 means invalid Longitude 39 int39 172 1 9 deg 180 deg Value out of interval 180 180 means invalid Altitude 28 int28 211 0 1 mm 13421 7727m Value 13421 7728 means invalid ashtech Value 13421 7727 means this or higher value Reserved 20 bit20 239 0 Set to 0 0 er 0 unknown source Utilized transformation 3 uint3 259 0 7 1 RTCM 3 source 2 7 reserved Source clarification 10 bit10 262 u spe Undefined otherwise Descriptor counter N 8 uint8 272 0 255 N umber of characters in local datum See DF145 descriptor field Local datim descriptar g N char N 280 Alphanumeric characters to clarify used See DF14
34. 1 93 Reference day number Di 18 int18 104 2 7 Correction to inclination semicircles La 21 int21 122 220 Longitude of first ascension semicircles Ta 21 uint21 143 25 Reference time of longitude of first node seconds W 16 int16 164 27 Argument of perigee semicircles Dia 22 int22 180 29 Correction to mean value of Draconic period seconds dDta 7 int7 202 yu Speed of Draconic period change sec curcuit Reserved 5 bit5 209 d Af0 dt sec curcuit Clock Offset 10 int10 214 27 Clock offset seconds END TRANSPORT CRC 24 uint24 224 24 bit Cyclic Redundancy Check Total 248 3 6 9 Message SBAS Almanac This message contains SBAS almanac data for a given SBAS satellite For detailed information about SBAS almanac data please refer to the WAAS ICD document Output Logic on time on change on new Message Binary size 2 bytes 168 bits How to request PASHS ATM NAV lt Port Name ON x ALM Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR SAW Table 3 6 9 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number ashtech START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 anti 14 Message length in bytes Set to 16 for this message
35. 30 15 15 31 IL IL 32 1X 1X E 3 Capability mask The Capability mask is the combination of the Satellite mask and Signal mask for a given GNSS at a given time E 4 Cell mask For quite a long time to come or even forever some satellites from a given GNSS will transmit some set of signals while some other satellites from the same GNSS will continue to transmit another set of signals The Satellite and Signal masks described above can contain a number of cross cells that cannot correspond to the actual signal available or the signal cannot be acquired in the given environmental conditions To save room in the ATOM observation messages the Cell mask has been introduced shtech The Cell mask is a bitset the length of which is Nsat Nsig where Nsat is the number of satellites the number of 1 s in the Satellite mask and Nsig is the number of signals the number of 1 s in the Signal mask The Cell mask indicates if the cross cell for a given satellite amp signal combination actually contains any data Cell mask 1 means it does Signal data are generated only for those satellite amp signal combinations where Cell mask 1 E 5 Example of building Satellite Signal and Cell Masks Let us consider building masks for the GPS it works similarly for all the other GNSS For the current epoch let the LI amp L2 amp L5 GPS tracking status be as follows Sats 1 3 6 7 13 15 32 are tracked and prov
36. ANP OWN PASHS ANP OUT RTCM 3 MT 1008 Table 3 5 2 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number ashtech START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 4 is reserved for ATOM ATR message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which ATR message follows ATR message type 9 uinto 55 0 511 Em to the antenna raw data corresponds 3 refers to physical antenna MESSAGE DATA Descriptor counter N 8 uint8 0 31 2 2 of characters in antenna descriptor DF029 desedpiat g N char N Alphanumeric characters describe antenna DF030 descriptor 0 Use standard IGS Model DF031 panna sep ID 8 un gt 1 255 Specific Antenna Setup ID Serial number counter Number of characters in antenna serial DF032 8 uint8 0 31 M number field m 8 M char M Alphanumeric characters describe antenna DF033 serial number END TRANSPORT CRC 24 uint24 24 bit Cyclic Redundancy Check CRC Total 3 5 3 Message Receiver attributes as
37. ATOM 18 24 Anezampleof ATOM PVT architeet ur rasen Reale 20 2 5 An overview of RNX observation message nee nn ee reine 23 MESSAGES DESCRIPTION 27 3 1 IMessapes generalion mechamis n een 28 32 Data Field Conventione ann Rain 29 33 Satellite Signal and Cell LT c 32 34 ATOM Message Cr 33 3 4 1 ATOM Sub Block Position Message ee 41 3 4 2 ATOM PVT Message Sub Block Accuracy message ns ek 44 3 4 3 ATOM PVT M ssag Sub Block Velocity HIBSSABB nee ae u ee 46 3 4 4 PVT Message Sub Block Clock message 49 3 4 5 PVT Message Sub Block Latency ee 51 3 4 6 ATOM PVT Message Sub Block Attitude message sn ne 53 3 4 7 Message Sub Block Baseline message na a a 55 3 4 8 ATOM Message Sub Block Miscellaneous message nen ae 57 3 4 9 PVT Message Sub Block Supplementary Attitude Dita u a 58 34 10 ATOM PVT Message Sub Block Baseline Supplementary Data 1 eise te eese teretes ee 60 3 4 11 ATOM PVT Message Sub Block Pseudo range residuals message aan ee 62 3 4 12 PVT Message Sub Block Satellite
38. GNSS signal s directly using internal receiver algorithms These are GNSS observables and navigation data as well as internal receiver positioning results On the other hand some ATOM fields refer to receiver hardware configuration or user entered parameters For example a lot of generated attributive information refers to either receiver configuration e g receiver name serial number firmware version etc or to some user entered settings e g antenna name antenna offset against ground mark ASCII message fixed reference position etc ushtech While the general organization of all the ATOM groups is similar there are however some differences Messages or groups SUP ATR NAV DAT STA and EVT are always generated independently of each other At the same time messages of groups RNX and PVT can be output differently Each of these groups contains a unique header often defining which data blocks follow this header If for example a receiver is configured to generate more than one block of data for a given group these data blocks can be grouped within a single message under the same header and inside the same transport frame or can be split into sequential and independent transmissions In the latter case each independent message provides a so called multiple message bit allowing the decoding equipment to compile complete data epochs from sequential transmissions The next two sections give examples of different transmission strategies for thes
39. MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 1s reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which NAV message follows For NAV message type 9 uint9 55 0 511 this message set ta 13 MESSAGE DATA Data ID 2 uint2 64 Data ID SVPRN 8 uint 66 1 19 SBAS satellite number Satellite Health amp Status bitwise meaning is 10 Ranging On 0 1 Bitl Corrections On 0 1 Bit2 Broadcast Integrity On 0 Off 1 Bit3 Reserved Health 8 bit8 74 Bit4 7 SBAS provider ID 0 15 0 WAAS EGNOS 2 MSAS 3 13 Not assigned yet 14 15 Reserved X 15 int15 82 2600 Satellite ECEF X coordinates meters Y 15 int15 97 2600 Satellite ECEF Y coordinates meters Z 9 int9 112 26000 Satellite ECEF Z coordinates meters ashtech Vx int3 121 10 Satellite ECEF velocity X coordinates m s int3 124 10 Satellite ECEF velocity Y coordinates m s Vz 4 int4 127 60 Satellite ECEF velocity Z coordinates m s Almanac data reference time within the day 0 M untl 1 PS expressed in the SBAS time scale seconds Reserved 2 bit2 142 Set to 00 END TRANSPORT CRC 24 uint24 144 24 bit Cyclic Redundancy Check CRC Total 168 3 6 10
40. Message length in bytes MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 7 is reserved for RNX Version 3 uint3 40 0 7 version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 1 if more ATOM data follow See DF393 Multiple message bit 1 Bitl 55 0 1 tagged to the same physical time and reference station ID Reserved for Issue Of Data Station DF409 A uint3 56 Set to 000 DF415 Smoothing interval 3 did 59 0 7 The code carrier smoothing interval 0 position does not follow 1 compact position follows 2 extended position follows 3 full position follows Position presentation 2 uint2 62 0 3 Bit1 GPS data follow Bit2 SBAS data follow Bit3 GLONASS data follow GNSS mask 8 Bit8 64 0 255 Bit4 GALILEO data follow Bit5 QZSS data follow Bit6 BEIDOU data follow Bit7 8 reserved for other GNSS ashtech 0 GPS is primary ae 2 GLONASS is primar Primary GNSS system 3 0 7 y d mate m 6 BEIDOU is primary 1 3 4 5 7 reserved for other GNSS Time tag 21 bit21 75 See Tables 3 8 1b c d Diveroence free Indicates if more than one carrier DF414 8 1 96 0 1 was used code carrier smoothing indicator smoothing Cumulative session transmitting time 7 uint7 97 0 127 indicator FI
41. Reserved for other physical or virtual ports 23 Port X The data from virtual port X are packed 24 Port Y The data from virtual port Y are packed 25 Port Z The data from virtual port Z are packed 26 Reserved for other sources identifiers 65535 The ATOM DAT EXT message is universal Referring to physical receiver ports source description 0 1 2 etc it allows users to spy all data entering the receiver via its physical ports etc There is no need to parse the incoming data The coder just takes the appropriate part from the input stream buffer wraps it into an ATOM DAT EXT message which is then output via the desired receiver port s Thus ATOM DAT EXT is a very effective transport to do the following e Spy all receiver configuration oriented commands from whichever port without the need to parse them Spy incoming differential stream s without the need to decode them It is worth noting that being requested to be output via a given receiver port ATOM DAT EXT will not interfere with any other receiver message requested on the same port data packing methods are applied to additionally guarantee that the content of the spied data will not be recognized mechanically by other procedures The composite log file can then be easily processed to extract all the spied data for example to create a reference station raw data file The ATOM DAT EXT can be used for creating so called virtual ports It can be useful
42. UTC reference week number AtLS 8 int8 200 QZS UTC differences at reference time WnLSF 8 uint8 208 0 255 when leap second became DN 8 uint8 216 0 7 en when leap second became ALLSE 8 int 224 pius between QZS and UTC after ashtech END TRANSPORT CRC 24 uint24 232 24 bit Cyclic Redundancy Check CRC Total 256 3 6 17 ATOM NAV Message BDS ionosphere and time shift parameters This message contains BDS ionosphere and time shift parameters For detailed information about these parameters please refer to the Beidou ICD IOpen Service Signal B1I Version 1 0 December 2012 document Output Logic on time on change on new Message Binary size 44 bytes 352 bits How to request PASHS ATM NAV lt Port Name gt ON x amp GIT Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR ION Table 3 6 17 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unto 14 Message length in bytes Set to 38 for this message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number s
43. all satellites Compact L 3 Factional carrier 4 Fine pseudo range 5 Fine pseudo range Fractional carrier Fractional carrier Rough range same for all satellites Full L 6 Fractional carrier 7 Fine pseudo range 8 Fine pseudo range Integer cycle carrier Fractional carrier Fractional carrier Integer cycle carrier Integer cycle carrier Rough range same for all satellites 2 Explicit algorithm to restore original observables Regardless absolute value all original receiver measurements pseudo range and carrier phase observables expressed in meters corresponding to each particular Satellite at each particular instant appear as some compact cloud of a size Mmax Mmin lt dM where dM is mainly defined by dispersive components such as ionosphere Remind that each carrier phase is aligned to corresponding pseudo range at the initialization moment using the adjustment of needed integer number of cycles For observables to be unambiguously packed into ATOM RNX we require dM 327 68 m Carrier data can be a little bit more outside this area shtech In the most of the cases the condition above is valid but there can be theoretically some singular cases super high ionosphere conditions very specific receiver hardware biases obviously incorrect carrier phase initialization where this condition is not held It must be noted that such a cloud size limitation is not an exclusive attribute of ATOM RNX dat
44. and interval can be set independently No more than one RNX scenario can be requested on the same receiver port RNX messages with same or different scenarios intervals can be requested on different receiver ports The default RNX scenario and interval can be receiver type and or firmware version dependent As the ATOM protocol continues to evolve more available scenarios will be published Scenario SCN 0 depends on receiver capability firmware version and or available options All scenarios except SCN 0 suppose that only single signal data is generated for each GNSS amp Sat amp Band For example simultaneous generation of L2P Y and L2C pilot data or 2W and 2L in RINEX convention for the same Satellite is possible only for SCN O Each newly specified scenario or interval overwrites the previous setup for a given port 4 4 Encapsulation 4 5 Output to virtual port 4 6 ATOM RNX scheduling among different transmissions 4 7 ATOM version 4 8 Querying ATOM Setup 4 9 Multiple ATOM PVT generation When GNSS receiver is configured into advanced positioning modes e g RTK Heading or RTK Attitude where more than single solution is available then user still can request the primary position solution with standard setting PASHS ATM PVT lt Port Name ON OFF Per shtech At the same time secondary solution heading attitude and associated baseline result should be requested with additional message request Given message rep
45. different sections Add more clarifications for AF003 field 2 28 Jul 10 2013 Appendix J added Section 6 reduced Corrections made in different parts of text OCC message copied to EVT group Update of ATOM user Manual is branched from given release The previous release was branched from ver 1 12 REFERENCE DOCUMENTS Doc ID Document Name NMEA standard for communication between marine electronic devices RD2 RTCM recommended standards for differential GNSS service RTCM SC104 RD3 RTCM recommended standards for differential GNSS service RTCM SC104 RD4 GNSS firmware platform ICD RD5 ATOM Super Compact and Flexible Format to Store and Transmit GNSS Data RD6 The Receiver Independent Exchange Format RD7 GNSS firmware platform PSD Date 01 Nov 2008 20 Aug 2001 March 2012 N A 15 Sep 2008 22 June 2009 N A Version 4 00 23 32 Latest N A 3 01 Latest ashtech Author NMEA RTCM RTCM Ashtech I Artushkin A Boriskin D Kozlov the paper presented on ION GNSS 2008 Werner Gurtner Lou Estey Ashtech ashtech CONTENT 1 WHBHALISATOM AND WEHAFLANTI DO en E aR 16 2 ATOM ORGANIZA TION OVERVIEW een sea euere ee 17 2 1 Basic ATOM de ee eier 17 2 2 Wrapping basic EEEE OKEE SESE SEATER 18 2 3 Short
46. etc each integer minute but less than 15 min See also PASHR LTN Table 3 4 5 a Sub Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Set to 3 Block ID 4 uint4 8 0 15 Set to 5 4095 if not defined or invalid see also the Latency 12 uint12 12 1 ms 0 4095 table 3 4 55 Total 24 Table 3 4 5 b Mapping table for Latency En Effective interval interval Comment msec identifier 0 4087 0 4087 Nominal mode 4088 4088 5000 Latency is within 4 088 to 5 seconds 4089 5001 6000 Latency is within 5 to 6 seconds 4090 6001 7000 Latency is within 6 to 7 seconds shtech 4091 7001 8000 Latency is within 7 to 8 seconds 4092 8001 9000 Latency is within 8 to 9 seconds 4093 9001 10000 Latency is within 9 to 10 seconds 4094 gt 10000 Latency is gt 10 seconds but still valid 4095 Invalid latency Latency is not defined or invalid Note This latency presentation table is intended to report latency with good resolution for conventional PVT modes when latency is typically below 1 second On the other hand in specific positioning modes such as synchronous or Time Tagged RTK position latency is primarily defined by the data link latency which can reach 10 seconds in some cases When latency is too high then there is no need to
47. event in the receiver In some cases however there is no obvious interpretation as to what is behind such or such output principle For example event can be interpreted as on change if the event refers to a change in some receiver state Nevertheless in most cases the meaning is quite clear For example the PVT message is primarily output using the on time principle If for example it is requested at an interval of x 0 5 seconds then it will be output at receiver time tags corresponding to each integer and half an integer second In some specific cases the PVT message is output using the event principle If for example the receiver is configured to output the so called Time Tagged or synchronous RTK position then ATOM PVT will be tagged to events when new RTK base data arrive at the rover are decoded and processed by the engine But since in most cases base data arrive at the rover with equal intervals and stable latency on event principle is here somehow equivalent to the on time principle DAT messages are output using change principle i e there is no need to specify an interval for outputting them Each message is generated once the content of the receiver data buffer containing corresponding data has been updated i e changed In order to have unified serial interface pattern one still can specify interval to output DAT messages bu
48. g SCN 0 2 4 In this case we do not need a priori information Reference value can be computed as Reference Nms R 1024 ms Range presentation 2 Rough range R follows and Nms is not available e g SCN 1 3 In this case one must use ephemeris and reference position to calculate the distance between base and Satellite CalcRange This value can have admissible error against real measurement up to about 0 5 ms to used to restore Nms Nms Function CalcRange 1024 ms shtech Range presentation 1 Rough range R does not follow Nms is not available e g SCN 100 In this case one must use ephemeris and reference position to calculate the distance between base and satellite CalcRange This value can have admissible error against real measurement up to 327 68 m to be used to restore full range and phase Reference Nms R 1024 ms Reference CalcRange Note that using receiver clock steered data we always guarantee that reference will be adequate to restore full range w o errors The below is an example of C source code which restores full pseudo range and carrier phase from ATM RNX fields This source code is provided only for illustration do not copy it to your application Nms number of ms dFineRange fine range within 0 655 36 m dFinePhase fine phase within 0 4096 cycles dRoughRang satellite rough range within 0 1023 1024 ms dFullRange Fu
49. inserting thereby this negligible error which does not affect the final performance If carrier phase for some signal is invalid then corresponding integer cycle carrier phase and fractional cycle carrier phase are both set to zero If carrier phase for some signal is valid but actually takes zero value then ATOM generator adds 1 256 or 1 1024 cycle for extended resolution cycle to it inserting thereby this negligible error which does not affect the final performance The observables reported for different resolution options are actually the same To transit from Extended to Standard resolution one simply ignores 2 LSB for fractional carrier 5 LSB for fine range and 4 LSB for SNR At the same time cumulative loss of continuity indicator for Standard resolution is 4 LSB of corresponding 10 bits indicator with Extended resolution With incorrect initialization and or singular ionosphere conditions carrier phase can diverge with time against respective pseudo range by large value which can no longer allow effective data packing into ATM RNX w o reinitializing new integer value in carrier phase In these cases ATM RNX generator can apply new integer value i e introduce cycle slip in respective carrier This integer value is either 1024 or 1024 cycles of respective wavelength and it can be not indicated by cumulative loss of continuity indicator Decoding equipment must be aware about such a possibility and foresee the actions either to reset correspondi
50. intervals can be enabled disabled using the following command PASHS ATM ATR lt Port Name gt ON OFF The general organization of the ATR message is presented in Figure 4a and in Table 4a Start Message Message Data Transport Header Transport 3 E 5 ro 3 bytes Figure 3 5 a ATR messages organization Table 3 5 1 a messages organization Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 ashtech Message sub number 4 uint4 36 0 15 4 is reserved for ATOM ATR message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 ATR message type 9 uint9 55 0 511 Specifies which ATR message follows MESSAGE DATA Attribute content See sub sections below END TRANSPORT CRC 24 uint24 24 bit Cyclic Redundancy Check CRC Total The supported ATR messages are presented in Table 4b Table 3 5 b Supported ATR messages ATR message ASCII identifier Attribute description Comments Counterpart type 1 ANM Antenna name Name setup ID an
51. is presented on Figure 3 7 a and in Table 3 7 a Start Message Message Data Transport Header 9 Transport 3 ur cd 5 be 3 bytes Figure 3 7 DAT messages organization Table 3 7 a DAT messages organization Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code ashtech Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 6 is reserved for ATOM DAT message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 DAT message type 9 uint9 55 0 511 Specifies which DAT message follows MESSAGE DATA Raw Data content See sub sections below END TRANSPORT CRC 24 uint24 24 bit Cyclic Redundancy Check CRC Total The supported DAT messages are presented in Table 3 7 b Table 3 7 b Supported DAT messages DAT message ASCII identifier Attribute description Comments Counterpart type 0 RESERVED 1 GPS GPS raw navigation data 2 N A NER raw data from L1 CA 2 GLO GLO raw navigation data GLONASS signal N A 3 SBA SBAS raw nav
52. m follows Tatoos anala anarriar 1 4 19 Tacaastad if fall nhaca Data item Bits Data type Offset Scale Range Comments DF Number SIGNAL DATA Fine pseudorange data m AN uint20 N cen 0 02 0 655 34 2 Integer cycle carrier 22 10 12 2 Inserted if full carrier phase phase data Ncell times wint22 Neen 1 cycle 9 4025 eyele follows see notes below 0 PET M Fractional cycle carrier 10 uintlO N 4 1 1024 cycle 1023 1024 Inserted if fine or full carrier phase phase data Ncell times follows 10 Inserted if compact or full DF408 SNR Ncell times supplementary data follow Extended 64 Inserted if full supplementary data supplementary data Ncell times 5164 follow see section 3 8 6 Total Notes Table 3 8 4 b 5 ignal data for resolution 1 extended Considering Fine pseudo range data for example repeating this field means that the value of this field will be provided in succession for each of the signals for which the Cell mask is 1 see Table 3 8 2c With 20 available cells the field size will finally be 300 20x15 bits or 20 20 bits for extended resolution Each cell in the integer cycle carrier phase data field actually includes a 4 bit cumulative loss of continuity indicator 10 bits for extended resolution followed by the 12 bit integer cycle carrier phase as such shtech
53. of data throughput shtech Appendix G Miscellaneous Appendix H The summary of ATOM v 1 v2 differences It must be emphasized once more that Ashtech decoders supporting some ATOM version X can automatically support ATOM of each lower version But not vice versa Each ATOM generator supporting some ATOM version X can be configured to generate ATOM of each lower version say to insure backward compatibility with legacy decoders 3rd party equipment can also effectively support each ATOM version by analyzing ATOM version number field provided in each ATOM message in the header Legacy decoding equipment must not process the data if unknown ATOM version number is detected in the header of these messages the messages described in given Manual refer to ver 1 with the only exception for ATM PVT block SVS and ATM RNX block GNSS observables messages They can be generated as ATOM ver 1 and as ATOM ver 2 messages The subsections below summarize the difference H 1 Satellite and Signal Masks in SVS block The size of Satellite and Signal mask is extended from 40 and 24 in v 1 to 64 and 32 in v 2 respectively See Section 3 4 10 and Tables 3 4 10 a and b 2 Satellite and Signal Masks ATOM RNX GNSS observables block The size of Satellite mask is extended from 40 in v 1 to 64 in v 2 Initially reserved 8 bits in v 1 are added to Signal mask in v 2 converting it from 24 bit v 1 to 32 bit v 2
54. radians GALILEO 32 uint32 326 ge See Note 1 Square root of the semi major axis Unit DF303 meters GALILEO t 14 uint14 356 60 983 040 Ephemeris reference time Unit seconds DF304 GALILEO 16 int16 a See Note 1 Amplitude of the cosine harmonic DF305 370 correction term to the angle of inclination Unit radians GALILEO 32 int32 386 27 See Note 1 Longitude of ascending node of orbital DF306 plane at weekly epoch Unit semi circles GALILEO C 16 1116 27 See Note 1 Amplitude of the sine harmonic correction DF307 418 term to the angle of inclination Unit radians GALILEO 1 32 int32 434 s See Note 1 Inclination angle at reference time Unit DF308 semi circles GALILEO 16 int16 P See Note 1 Amplitude of the cosine harmonic DF309 468 correction term to the orbit radius Unit meters GALILEO o 32 int32 484 17 See Note 1 Argument of Perigee Unit semi circles DF310 24 int24 gm See Note 1 Rate of right ascension Unit semi DF311 GALILEO 516 circles sec OMEGADOT GALILEO 10 int10 540 2 See 1 Broadcast Group Delay E5a E1 DF312 GALILEO BGDgswe1 10 int10 550 27 See 1 Broadcast Group Delay E5b E1 DF313 ashtech GALILEO NAV 2 bit 2 Unitless reserved DF316 SIGNAL HEALTH 560 STATUS OSHS GALILEO NAV 1 bit 1 Unitless reserved DF317 DATA VALIDITY 562 STATUS OSDVS Transmission Time of 20 uint20 0 604799 Ful
55. report it with ms resolution e The reported latency refers to the delay of ATM PVT output instance compared to the ATM PVT time tag This reported latency is unique for given ATM PVT message and may differ from the latency reported in PASHR LTN message ashtech 3 4 6 PVT Message Sub Block Attitude message This sub block contains attitude parameters Output Logic on time Sub block Binary size 11 bytes 88 bits How to request PASHS ATM PVT lt Port Name gt ON x amp HPR Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also PASHR ATT GPHDT Table 3 4 6 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Set to 11 Block ID 4 uint4 8 0 15 Set to 6 Heading 16 uintl6 12 0 360 Value gt 360 means not defined or invalid Pitch 16 intl6 28 0 01 90 Value gt 90 amp Value lt 90 means not degree defined or invalid Roll 16 int16 44 0 01 90 Value gt 90 amp Value lt 90 means not degree defined or invalid Calibration mode 1 bitl 60 0 1 an 1 operation mode 5 0 fixed ambiguity Ambiguity flag 1 bitl 61 0 1 1 float ambiguity 0 2 arbitrary moving antennae 1 2 tightly moving antennae ve 2 3 tightly moving antennae 3 4 tightly moving a
56. signals while some ID values may be indicated as Reserved in this standard These IDs may be used in the future for other signals and thus decoding software shall ensure that it does not skip these bits but decodes complete GNSS Signal mask decodes corresponding observables as if they refer to known signals but should refrain from using them unless new signal mapping table becomes available to map corresponding ID to a specific signal If signal observable with ID n is available for at least one of transmitted satellite then corresponding bit number is set to 1 otherwise corresponding bit is set to 0 This filed represents a two dimensional table which determines signal availability for each transmitted satellite This field is of variable size X Nsig Nsat where Nsat is the number of Satellites the number of those bits which are set to 1 in Satellite mask DF394 and Nsig is the number of available signals the number of those bits which are set to 1 in Signal mask DF395 The first row of this rectangular table corresponds to the Signal with the smallest ID among those for which corresponding bit in Signal Mask is set to 1 The second row corresponds to the Signal with the second smallest ID among those for which corresponding bit in Signal Mask is set to 1 The last row corresponds to the Signal with the highest ID among those for which corresponding bit in Signal Mask is set to 1 The first
57. than 999 See also PASHR SAL Table 3 6 12 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 ano 14 Message length in bytes Set to 32 for this message MESSAGE HEADER ashtech Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 9 we s Species which message follows Fo MESSAGE DATA SVPRN 6 uint6 64 0 77 Satellite PRN ROOT_A 24 uint24 72 yu Square root of semi major axis meters al 11 int11 96 amos Clock correction sec sec a0 11 int11 107 Clock correction sec OMEGAO 24 int24 118 Em Longitude of ascending node semicircles E 17 uintl7 142 p Eccentricity For MEO IGSO satellites 1020 30 semi i 16 int16 159 29 circles for satellites i0 0 00 semi circles OMEGADOT 17 int17 175 Rate of right Asc semi circles per sec Q 24 int24 192 2 Argument of Perigee semi circles 24 int24 216 PES ze at reference time
58. the receiver and firmware version That is why the reader should not only understand the content of an ATOM message but also learn how it can be requested and output from a receiver For a complete description of the ATOM serial interface please refer to the corresponding section shtech 3 1 Messages generation mechanism Any ATOM message can usually be generated onto any available receiver port independently of each other When describing the serial interface we mention Port Name as a substitute for the actual receiver port A B etc The same ATOM message can be requested through more than one port and possibly with different intervals and parameters The time priority of one ATOM message over another ATOM message within the same epoch can be receiver firmware dependent The time priority of ATOM messages against non ATOM data within complete epoch data is also receiver firmware dependent When requested each ATOM message is generated using a specific combination of the following principles Onnew Onchange e Ontime Onevent new means that the corresponding message is output immediately after being requested change means that the corresponding message is output only after its content has changed On time means that the corresponding message is output on a regular basis according to the requested time interval x event means that a message can be generated with its content tagged to some
59. trade off between data quality availability and message throughput These different forms of data presentation can be available through the so called SCN x scenario where integer x stands for the scenario number RNX messages can then be enabled disabled through a single command PASHS ATM RNX lt Port Name gt ON OFF lt Per gt amp SCN x ashtech The table below shortly describes the scenarios currently supported for more details please refer to Section 5 and Appendixes C through F User case SCN x Comment Notes Raw data recording 0 All available raw data in full presentation full computed reference position follows each epoch Standard differential protocols 1 Singe band pseudo range and carrier phase in full presentation Nms in ranges The generalized analog of RTCM 3 MT 1001 1009 1006 does not follow extended fixed position follows each 12 epochs Can support L1 only L2 only L5 only etc generation 2 Singe band SNR pseudo range and carrier phase in full presentation extended The generalized analog of RTCM 3 MT 1002 1010 1006 fixed position follows each 12 epochs Can support L1 only L2 only L5 only etc generation 3 Dual band pseudo range and carrier phase in full presentation Nms in ranges The generalized analog of RTCM 3 MT 1003 1011 1006 does not follow extended fixed position follows each 12 epochs Can support L1 amp L2 as well as L1 amp L5 or any other dual band
60. type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code ashtech Reserved 6 bit6 8 Set to 000000 Message Length 10 and 14 Message length in bytes Set to 66 for this message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 message type 9 9 55 0 511 Specifies which NAV message follows For this message set to 1 MESSAGE DATA umn a tized essere 12 uint12 64 Set to 1019 number SVPRN 6 uint6 76 1 32 Satellite PRN number DF009 Wn 10 uintl0 82 0 1023 GPS week number DF076 Accuracy 4 uint4 92 User range accuracy DF077 00 reserved DF078 01 P code ON Code on L2 2 bit2 96 10 C A code ON 11 L2CON Idot 14 int14 98 p Rate of inclination semicircles sec DF079 Iode 8 uint8 112 Orbit data issue DF071 Toc 16 uint16 120 16 Clock data reference time sec DFO081 af2 8 int8 136 go Clock correction sec sec DF082 afl 16 int16 144 Clock correction sec sec DF083 22 int22 160 a Clock correction sec DF084 Iodc 10 uintl0 182 Clock data issue DF085 Crs 16 int16 192 97 Harmonic correction term meters DF086
61. update rate Supporting different customization options from maximally compact to maximally full Being in line with existing RTCM 3 and NMEA messages as well as RINEX 3 format Backward compatibility with legacy Ashtech proprietary messages Easily upgradable to include new versions and or new messages Universal presentation form for different GNSS data Capability to use ATOM for raw data recording and as a differential correction protocol ATOM can be used as the only GNSS data source for different applications It can also be used in conjunction with existing including legacy Ashtech proprietary and standardized data protocols The use of a standardized RTCM 3 transport layer allows 3 party software to detect synchronize ATOM messages easily Depending on their applications users can take advantage of some particular ATOM messages e g receiver positioning results only or use the full ATOM function including generating raw data providing reference data base mode and many others GNSS has grown rapidly in recent times More and more GNSS related applications have appeared and new requirements for GNSS data have been formulated Particularly e Ease of use and universal support of different GNSS and their signals e Generating data with high update rate e Allowing compact data presentation to save room on the storage device and or data link bandwidth ATOM meets all these new requirements ashtech 2 ATOM ORGANIZATION OVERVIEW
62. used 102 3 if not defined or invalid HDOP 10 uintl0 44 0 1 0 102 2 Corresponds to satellites used 102 3 if not defined or invalid E NUR 38 int38 54 0 1 mm 13743895 3471 13743895 3472 m if not defined or DF025 m invalid Y coordinate 38 int38 92 0 1 mm 13743895 3471 13743895 3472 m if not defined or DF026 m invalid Z coordinate 38 int38 130 GR 13743895 3471 13743895 3472 m if not defined or DF027 m invalid Age of differential corrections applied Differential position age 10 uintl1O 168 1 sec 0 1023 to PVT 1023 if not defined or invalid 1022 if valid but 21022 Base ID 12 uint12 178 0 4095 Base station ID DF003 Position type clarifier 4 uint4 190 0 15 See Appendix G AF003 Age of differential data link 1023 if Differential Differential link age 10 uint10 194 1 sec 0 1023 not defined or invalid 1022 if valid but link age 21022 Reserved 4 uint4 204 See Appendix G AF023 Total 208 Notes ashtech If invalid fix is reported some supplementary fields e g Base ID or differential age can still have some sense If position is invalid then position type clarifier AF003 contains the cause of invalid position With at least one GPS or GLONASS or GALILEO or QZSS or SBAS or BeiDou ranging satellite used in the position computation the corresponding bit is set accordingly In differential SBAS the base station ID is the PRN of the master or primary SBAS 120 158 Some fields have a reserved state meaning not
63. words the representations of the numbers 7 and 7 in a binary form are 10000111 and 00000111 respectively Negative zero is not used 3 6 5 Message SBAS Ephemeris This message contains SBAS ephemeris data for a given SBAS satellite For detailed information about SBAS ephemeris data please refer to the WAAS ICD document Output Logic on time on change on new Message Binary size 39 bytes 312 bits How to request PASHS ATM NAV Port Name ON x amp EPH Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR SNW Table 3 6 3 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number ashtech START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 anti 14 Message length in bytes Set to 33 for this message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 message type 9 uint9 55 0 511 Specifies which NAV message follows For this message set to 3 MESSAGE DATA SVPRN 8 uint8 64 SBAS satellite number Iode 8 uint8 72 Issue of data Epheme
64. 000 This means that the receiver generates data for Nsat 7 satellites with Sat IDs 1 3 6 7 13 15 and 32 Then the Signal mask is decoded as the following 32 bit sequence 01010000010000100000000000000000 This means that the receiver generates up to Nsig 4 signals of types 2 4 10 and 15 see signal types definition in the table in section E 2 Then the size of the Cell mask that follows is known to be 28 4x7 shtech And finally the Cell mask is decoded as the following 28 bit sequence BITSET 1111111011101001111010011111 After that the satellite and signal data that follow should be identified correctly To do this the following steps should be taken 1 With 7 satellites received for up to 4 different types of signals the Cell mask should be split into seven equal parts Sub BITSET 1111111011101001111010011111 1 2 3 4 5 6 7 First 1111 Second 1110 Third 1110 Fourth 1001 Fifth 1110 Sixth 1001 Seventh 1111 One can see that the length of each Sub BITSET is equal to the number of the different tracked signals Nsig 4 The first Sub BITSET tells us that satellite 1 provides signals 2 4 10 15 The second Sub BITSET tells us that satellite 3 provides signals 2 4 10 The third Sub BITSET tells us that satellite 6 provides signals 2 4 10 The fourth Sub BITSET tells us that satellite 7 provides signals 2 15 The fifth Sub BITSET tells us that satellite 13 provides signals 2 4 10 2095 G
65. 11 Specifies which NAV message follows For this message set to 11 MESSAGE DATA SVPRN 5 uint5 64 0 31 Satellite PRN number Health 8 uint8 69 Satellite Health E 16 uint16 77 y Eccentricity ashtech Toa 8 uint8 93 24 Reference time of almanac 19 Inclination at reference time relative to Ai b 2 10 0 3 semi circles OMEGADOT 16 int16 117 Rate of right Asc semi circles per sec ROOT A 24 uint24 133 2 Square root of semi major axis meters OMEGAO 24 int24 157 2 Longitude of ascending node semicircles Q 24 int24 181 Argument of Perigee semi circles 24 int24 205 223 Mean anomaly at reference time semi circle 11 intll 229 20 Clock correction sec Afl 11 int11 240 m Clock correction sec sec Wna 8 uint8 251 1 0 255 Almanac week number Reserved 9 615 259 Set to 00000 END TRANSPORT CRC 24 uint24 264 24 bit Cyclic Redundancy Check CRC Total 288 Note The value of Ai generated from field io Inclination Angle at Reference Time from GPS Ephemeris data is scaled by 0 1 3 6 5 Message GLONASS Almanac This message contains GLONASS almanac data for a given GLONASS satellite For detailed information about GLONASS almanac data please refer to the GLONASS ICD ver 5 document Output Logic on time on change on new Message Binary size 31 bytes 248 bits How to request PA
66. 21 cells to generate In order not to occupy empty room for 7 untracked shaded cells the Cell mask is additionally created as shown below The first table is a copy of the previous one in which all the columns not containing any signal as well as all the rows not containing any satellite have been removed The resulting binary table in green is what we call the Cell mask Signals shtech The table below shows the same mask but presented by a single bitset as it must be interpreted by coding decoding equipment The size of the cell mask is Nsig Nsat 4 7 28 while the number of available cells with observables is Ncell 21 Signal ID 155 4 1015 2141101 15 2 4 10 15 2 4 10115 2 4 10 15 2 4 10 15 2 4 10 15 Sat ID 1 1 1 1 3 3 3 3 6 6 6677 7 7 13 1 13 13 15 15 15 15 32 32 32 32 Cell mask The above tables show how the complete 24 40 bits but too sparse status table can be presented by 3 bitsets Fixed size 64 bit Satellite mask e Fixed size 32 bit Signal mask Float size Nsig Nsat Cell mask 4 7 bits in the above example E 6 Example of interpreting Satellite Signal and Cell Masks Consider the example of GPS data described in E 5 Let us decode the Satellite mask as the following 64 bit sequence 1010011000001010000000000000000100000000000000000000000000000
67. 298 0 7 roni when leap second became Reserved 22 306 For future and wnt END TRANSPORT CRC 24 uint24 328 24 bit Cyclic Redundancy Check shtech ushtech Messages of the DAT raw DATa group contain original binary data Particularly this group contains GPS GLONASS Galileo QZSS BDS and SBAS raw navigation data streams Processing raw navigation data streams users can extract any navigation information particularly that contained in ATOM NAV messages Also group DAT contains very valuable generalized message EXT and INT capable to output almost any data existing travelling inside GNSS receiver All DAT messages containing navigation streams can be requested independently of each other For messages of this group there is no need to specify intervals between messages while it still can be specified by universality reasons in which case it will be ignored message is output after a new frame has been decoded DAT EXT messages are requested by single command and output every data entering GNSS receiver i e DAT EXT contains spied data packed into convenient frames DAT INT messages are also requested by single command For each hardware target and firmware version there can be different set of DAT INT messages The set of default ATOM DAT messages can be enabled disabled using the following command PASHS ATM DAT lt Port Name ON OFF The general organization of the DAT message
68. 3 NAV Message SBAS uses pipa n EY PRAYER LEV CLR RE saa Ia PORRO 94 3 6 4 ATOM NAV Message Galleg Epheimens aus aka 96 3 6 5 ATOM NAY Message see ee 100 3 6 6 ATOM NAV Message Beidou aueh 102 3 6 7 ATOM NAV Messages GPS Altana nee 105 3 6 8 ATOM NAV Message GEONASS ee aan 106 3 6 9 ATOM NAV Message SBAS one een seele en 108 3 6 10 ATOM NAV Messare Gall Amann ee een essen 110 36 11 ATOM NAV Message QZSS Almanae un 112 3 6 12 NAV Message Beidou Almanac zn ee 114 36 13 NAV Message GPS ionosphere and time shift Paare rn 116 3 6 14 NAV Message GPS full time parameter ie 118 3 6 15 NAV Message GAL ionosphere and time shift parameters nennen nasananenn sau ee ko annehmen 119 3 6 16 NAV Message QZS ionosphere and time shift parameters a 121 3 6 17 NAV Message BDS ionosphere and time shift trennen nnne 123 3 7 ATOM DA dM SS ee nee een 126 3 7 1 ATOM DAT Message GPS Raw Sub Frame uses ee ei 128 3 7 2 ATOM DAT Message GLONASS Raw Stripe ee a ee 128 3 7 3 ATOM DAT Message SBAS Sub ana aa 128 3 7 4 ATOM DAT Message Galileo Raw Pas nen ee ehe 130 3 7 3 ATOM DAT
69. 5 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also N A Table 3 4 10 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 Uint8 0 0 255 Set to 19 Block ID 4 Uint4 8 0 15 Set to 10 Sigma 20 uint20 12 0 001 m 0 1048 574 m 1048 575 if not defined or invalid 7 uint7 32 1 128 0 1 Have meaning only if Sigma is valid K2 7 uint7 39 1 128 0 1 Ditto K3 7 uint7 46 1 128 0 1 Ditto R12 8 int8 53 1 128 1 1 Ditto R13 8 int8 61 1 128 1 1 Ditto R23 8 int8 69 1 128 1 1 Ditto i i 0 time 1 d estimat 10 Uint1O 7 10ms 0 10230ms 18 ume tagged 1 10230 means 10230 BaseID 12 Uint12 87 0 4095 Reserved 5 Bit5 99 Set to 00000 Reserved 48 Bit48 104 Set to 0 0 shtech Total 152 This sub block refers to the data presented in the baseline BLN sub block described above It contains parameters allowing the complete baseline covariance matrix symmetric positive definite to be restored It is assumed that base coordinates are quite accurate and do not insert extra error into baseline estimate The covariance is defined as sll 512 513 5 522 523 where s11 s22 and 533 are always positive other terms can be negative s33 Here indexes 1 2 and 3 refer to 1 274 and 3 baseline comp
70. 6 local datum name Total Notes Negative latitude means South positive latitude means North Negative longitude means West positive longitude means East Negative altitude means below ellipsoid positive altitude means above ellipsoid In some cases reported Cartesian coordinates can be invalid while Geographic coordinates are valid Or vice versa Decoding equipment must track this situation by checking fields for invalid states Utilized transformation source and its clarification currently support RTCM 3 transformation messages But these fields can be utilized in future to indicate other sources and clarifiers Field DF148 contains the information about particular utilized RTCM transformation messages 1023 through 1027 used in position reported in this block ashtech 3 4 14 ATOM PVT Message Sub Block Custom datum clarification This sub block contains the clarification name and parameters of the datum in which COO position is expressed There is no need to request this block specially each time when field datum in MIS block 15 set to 1 custom all clarification parameters are generated in given block Output Logic on time Sub block Binary size depend on message content How to request PASHS ATM PVT lt Port Name gt ON x amp COO Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also Table 3 4 14 a Sub Message structure and content
71. 6 1980 rolls from 4095 to 0 if GPS is primary system The number of GNSS time cycles refers to GLONASS day number 1 1461 day 1 corresponds to January 1 1996 rolls from 1461 to 1 zero means unknown day values 1462 4095 are not used if GLONAS is primary system The number of GNSS time cycles refers to BDS Week number 0 4095 0 starts midnight January 1 2006 Sunday rolls from 4095 to 0 if BDS is primary system In all the cases antenna height refers to the vertical distance between Antenna Reference Point and Ground Mark ATOM PVT Message Sub Block Supplementary Attitude Data This sub block contains supplementary information to HPR sub block such as attitude rate attitude accuracy and some other valuable indicators User can request it additionally if HPR information is not sufficient for his her application ashtech Output Logic on time Sub block Binary size 13 bytes 104 bits How to request PASHS ATM PVT lt Port Name gt ON x amp ROT Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also N A Table 3 4 9 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 Uint8 0 0 255 Set to 13 Block ID 4 Uint4 8 0 15 Set to 9 Heading speed 16 int16 12 0 01d s 327 67 d s 327 68 means invalid Pitch spe
72. 99 See also PASHS ANP PASHS ANH Table 3 5 5 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Niessage Length 10 untio 14 Message length in bytes Set to 16 for this message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 4 is reserved for ATOM ATR message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which message follows For ATR message type 9 uint9 55 0 511 this niessdde 21 MESSAGE DATA Slant 16 uint16 64 0 0001 0 6 5535 m Antenna slant Radius 16 uint16 80 0 0001 0 6 5535 m Antenna radius Vertical offset 16 uint16 96 0 0001 0 6 5535 m Antenna vertical offset ashtech Horizontal azimuth measured from the antenna ground mark to the survey point Horizontal azimuth 24 uint24 112 0 0001 0 6 2831 rad with respect to the WGS84 north Unit in radians Horizontal Offset 16 uint16 136 0 0001 0 6 5535 m Antenna horizontal offset END TRANSPORT CRC 24 uint24 152 24 bit Cyclic Redundancy Check CRC Total 176 3 5 6 Message
73. ASHS ATM lt Group type gt lt Port Name gt ON where lt Group type gt is any of the available messages ALR SUP PVT ATR NAV DAT RNX STA or EVT lt Port Name gt is any of the supported receiver ports A B etc Using this type of request default data outputs will be available Examples of default outputs are given in the table below defaults may be receiver firmware dependent 4095 ATM Group type subID subID Default sub messages sub blocks or scenario Default intervals Receiver Alarms 0 ALR USR N A Supplementary data 1 SUP CPI 1 second Positioning results 3 PVT COO ERR LCY SVS 1 second for all Receiver attributes 4 ATR ANM RNM CPB 30 seconds for all Navigation information 5 NAV EPH GIT GFT 300 seconds for all Binary data frames 6 DAT EXT FRM N A Receiver observables 7 RNX SCN 4 1 second Receiver status 13 STA BLA DDS GFN 5 seconds for all Receiver events 14 EVT TTT PTT N A With each receiver reset the configuration sub blocks sub messages and their intervals of each group is set to respective defaults To request the output of any ATOM message a specified port at desired output rate period use the following command PASHS ATM Group type gt lt Port gt lt gt shtech where lt Per gt 15 the period in sec of the group 1 of each default sub message or sub block The period specified for ALR and DAT messages 15 ignored
74. Although a proprietary message ATOM uses the standardized RTCM 3 transport layer This decision was made to allow any 3 party vendor to decode ATOM using available RTCM 3 decoders 2 1 Basic ATOM transport RTCM 3 message numbers range from 1001 to 4095 Numbers 4001 through 4095 are reserved for proprietary usage Each vendor can ask RTCM to assign a unique number from this range to be used exclusively for its own data The number 4095 is reserved for Ashtech and is used by ATOM As a result the transport layer used by ATOM is the same as the one of any standardized RTCM 3 message Message Length Variable Length Data Message 1 Marable Length Dane Variable length integer number of bytes Variable length integer number of bytes The 8 bits 6 bits 10 bits Known message 4095 ATOM is here content can be unknown for older ATOM 24 bits versions Not defined setto Message length QualComm definition 11010011 000000 0 1023 bytes as specified in Message Length block CRC 240 Similarly to RTCM 3 ATOM reserves a possibility for potential future extension for each existing ATOM message These extensions may be introduced by adding data to the end of any ATOM message This flexibility leads to the following claims e Actual message length as decoded from message header may not match be greater than the minimal required message length as dictated by the content of any particular ATOM message e Decoding software shall omit ignore any extra b
75. C setting would affect header decimation in the same manner as it affects decimated pseudo ranges and carrier phases It must be emphasized that the decimation option is implemented in an adaptive way 1 it does not use fixed decimation freezing intervals On the contrary it applies some flexible strategy depending on the current situation at the reference site As for the decoder on rover side it does not make any a priori assumptions regarding the data decimation scenario used on reference side On the contrary all the information about the data presentation form is extracted from the ATOM message itself Although the decimation option allows the reduction of the mean throughput it does not however allow the reduction of the peak throughput However for many data links e g GPRS it is the mean throughput that really matters The decimation technique described above for RNX observations data is equally applicable to BAS corrections data shtech Appendix E Data identifiers ATOM RNX observables E 1 Satellite mask Satellite mask is a bitset indicating which satellites from a given GNSS provide at least one signal it does not matter which The Satellite mask contains 64 positions for each GNSS Currently GPS occupies 32 positions but up to 63 PRNs are claimed for future GLO occupies 24 positions but theoretically 28 slots for FDMA can be available for CDMA there can be even more SBAS reserves 19
76. DF083 22 int22 160 ga Clock correction sec DF084 Iodc 10 10 182 Clock data issue DFO85 Crs 16 intl6 192 27 Harmonic correction term meters DF086 An 16 int16 208 gt Mean anomaly correction semicircles sec DF087 m0 32 int32 224 23 anomaly at reference time DF088 semicircles Cuc 16 int16 256 2 Harmonic correction term radians DF089 E 32 uint32 272 2 Eccentricity 090 Cus 16 int16 304 Harmonic correction term radians DF091 32 uint32 320 p Square root of semi major axis meters 2 DF092 Toe 16 uint16 352 16 Reference ephemeris time DF093 Cic 16 int16 368 gee Harmonic correction term radians DF094 00 32 int32 384 2 Longitude of ascending node semicircles DF095 Cis 16 int16 416 2 Harmonic correction term radians DF096 10 32 int32 432 2 Inclination angle semicircles DF097 Crc 16 int16 464 p Harmonic correction term meters DF098 32 int32 480 27 Argument of perigee semicircles DF099 dot 24 int24 512 am Rate of right ascension semicircles sec DF100 TER i zus 2 2 u ashtech The MSB shall indicate a summary of the DF102 health of the NAV data Heath 6 uns 592 The five LSBs shall indicate the health of the signal components L2 P data flag 1 550 As there is 2 code bit is fixed at DF103 When curve fit interval is set to 0 the DF137 Ephemeris data are effective for 2 hours Fit Interval 1 bitl 551 When the curve f
77. ET SAH RIO CFG CPB NAV EPH 6 ALM 6 GIT 4 GFT DAT GPS GLO SBA GAL EXT INT FRM STA BLA DDS DPS RSA RSP EGB DLS GCO SHI AST SSC EVT TTT PTT It must be noted once more that some sub messages sub blocks can be not not supported by Ashtech GNSS firmware But they can be supported by Ashtech field and or office application software Also some sub blocks e g LDP CDC and LMP cannot be requested separately and are generated automatically in some conditions as a supplement to other sub blocks e g COO It should be noted that when requesting the EPH sub message one actually gets EPH for multiple GNSS GPS GLO SBA GAL QZS BDS if all are tracked There is no way to request EPH data separately for each GNSS The same is true for ALM data Also if a user requested raw data reduction to the virtual antenna e g ADVNULLANTENNA and asks for the ANM sub message two different ANM messages will result one for the physical antenna and the other for the virtual antenna the reported observables data correspond to shtech Below are typical examples to enable some ATOM data outputs the examples suppose that the PASHS ATM ALL lt Port name gt OFF command has been run previously Enable data on port A with position followed by accuracy both at 0 1 second interval and by satellite status at 1 second interval PASHS ATM PVT A ON 0 1 amp COO ERR PASHS ATM PVT A ON 1 amp SVS Enable
78. Full fine carrier phase data is just asum of integer cycle carrier phase and fractional cycle carrier phase In some cases integer cycle carrier phase is not transmitted compact data transmission scenarios for static GNSS receiver so decoding equipment must take proper care to restore full fine carrier phase or operate with fractional carrier only The Cumulative loss of continuity indicator is incremented by each time when at least one non recovered carrier cycle slip occured for this particular signal on interval between currently generated and previously generated epoch The indicator takes values from 0 to 15 or 1023 and then back to 0 after 15 or 1023 has been reached ATM RNX data generator insures needed provision in order not to allow full indicator range cycle to occur during less than 2 minutes reported carrier phases of different signals belonging to the same band are aligned with each other i e a cycle correction is possibly applied Fine pseudo range data are usually smoothed properly Optional parameters smooth count and smoothing residuals are used to indicate the smoothing status and restore the unsmoothed fine pseudo range if needed If pseudo range for some signal is invalid then its corresponding fine pseudo range field is reported as zero If pseudo range for some signal is valid and corresponding fine pseudo range field actually takes zero value then ATOM generator adds 0 02 m or 0 02 32 m for extended resolution to it
79. G 5 added Detailed clarification of Signals and Satellite IDs is provided for GLONASS SBAS and GALILEO Message ATM DAT GAL finalized Message ATM DAT FRM introduced 2 08 August 30 2011 Field AF006 is reintroduced it is supposed that later user will use AF019 instead Message 4095 15 is introduced More clarifications for ATM PVT header IDs added Max age of DDS message clarified A comment added to carrier polarity indicator in RNX message 2 09 September 30 2011 DDS message modified Field AF012 clarified in Appendix Number of ATM PVT fields clarified BLN block now can report the assumption about applied clock drift model Field AF020 request ID is introduced in ATM PVT header Block ATM PVT ROT finalized shtech GPS and GLONASS almanac messages clarified Appendix G modified in different entries mainly to address field AF020 introduction FST group is renamed to SUP group Two messages of SUP group finalized Message STA GEN introduced 2 10 October 30 Message STA GEN finalized 2011 ATM DAT FRM message modified Messages ATR RIO and ATR CFG added Section 4 3 generalized Sections 5 3 and 5 4 generalized and clarified Section G 6 added 2 11 November LDP and CDC blocks ATM PVT are modified 30 2011 Section G 6 removed as it is now a part of GNSS f w platform PSD Section 4 edited Section 5 edited 2 12 December Section 3 8 edited 30 2011 Galileo EPH messag
80. GPS GLONASS SBAS GALILEO and QZSS then 5 SVS sub blocks will be generated sequentially under the same ATOM PVT header provided PVT message size is still below 1023 bytes The organization of SVS data is very similar to data organization in the ATOM RNX message see Section 3 8 and Appendix E Output Logic on time Sub block Binary size depends on the number of signals How to request PASHS ATM PVT lt Port Name gt ON x amp S VS Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also PASHR SAT GPGSV The complete SVS sub block for each GNSS includes three groups of data that are generated one after the other SVS header e Satellite data e Signal data Table 3 4 12 a SVS header for ATOM PVT version 2 Data item Bits Data type Offset Scale Range Comments DF Number SVS HEADER Block size 8 uint8 0 0 255 Set to 23 3 Nsat 2 Ncell Block ID 4 uint4 8 0 15 Set to 14 0 GPS 1 SBAS 2 GLONASS GNSS ID 3 uint3 12 0 7 3 GALILEO 4 QZSS 5 Beidou 6 7 reserved for other GNSS Satellite mask 64 Bit64 15 See Appendix E DF394 Signal mask 32 Bit32 79 See Appendix DF395 ashtech Cell mask 64 bit64 111 See Appendix E See DF396 Reserved 9 bit9 175 0 511 Set to 000000000
81. H Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also RTCM 3 Message 1046 Table 3 6 4 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code ashtech Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes Set to 71 for this message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 message type 9 9 55 0 511 Specifies which NAV message follows For this message set to 4 MESSAGE DATA Standardized message 12 uint12 If 1046 then the content below is valid DF002 64 ie a number Otherwise the content is wrong GALILEO Satellite 6 uint6 1 64 The GALILEO SV parameter is coded See DF252 ID with 6 bits However the max constellation 76 1 which can accommodated within the I NAV frames is 36 satellites 3 planes of 12 satellites each GALILEO Week 12 uint12 1 WEEK 0 4095 GALILEO week number Roll over every DF289 Number WN 82 4096 weeks about 78 years The start time for Galileo System Tim
82. I parameters user specified by receiver serial commands See Ashtech OEM products User Manuals User must understand that single frequency receivers cannot generate divergence free smoothing Typical Ashtech default smoothing intervals are 600 sec for single band receivers and 1800 sec for multiple band receivers Note 600 seconds for L1 only receiver it not so high value as one can think In fact Ashtech applies years proven L1 code carrier smoothing strategy using second order filtering That is why when first order filter can produce ionosphere bias even with 100 sec smoothing Ashtech second order filtering inserts no bias even with 600 sec smoothing Some Satellites at some time windows cannot provide L2 data While receiver can report divergence free smoothing user must realize that it cannot be applicable for L2 defective data Field Cumulative session transmitting time indicator shows the time elapsed since requesting given ATM RNX output Each time when command PASHS ATM RNX lt port gt ON lt period gt amp SCN lt scenario gt is issued even with the very same parameters as previously this field is reset to zero Processing equipment should interpret decreasing this indicator between 2 consecutive received epochs as a cycle slip for all carrier data The same physical time of two observation messages does not obligatory mean the very same time tagging because one message can be tagged to one GNSS time while the other message ca
83. LE MASK Incremented by 1 each time the content Data ID change counter 5 uint5 0 0 31 of capability or cell mask is changed rolls from 31 to 0 Data ID follow 1 bitl 5 0 1 0 no capability amp cell mask follow 1 capability amp cell mask follow 0 Nms follow Ny follow 1 0 1 5 1 Nms follow 0 no supplementary data follow Supplementary follow 2 7 0 3 1 compact supplementary data follow 2 full supplementary data follow 3 reserved 0 no pseudo range follow Pseudo range follow 2 9 0 3 1 fine pseudo range follow 2 full pseudo range follow 3 reserved 0 no carrier phase follow 1 fine carrier phase follow Carrier phase follow 2 uint2 11 0 3 2 full carrier phase follow 3 reserved 0 standard resolution i lin B a 1 extended resolution Reserved 2 bit2 14 0 3 Set to 00 Total 16 ashtech Table 3 8 2 b Capability mask for ATOM version 2 inserted if Data ID follow 1 in observable mask see Table 3 8 2a Data item Bits Data type Offset Scale Range Comments DF Number CAPABILITY MASK Satellite mask 64 bit64 0 See Appendix E DF394 Signal mask 32 bit32 64 See Appendix E DE Total 96 Table 3 8 2 c Capability mask for ATOM version I inserted if Data ID follow 1 in observable mask see Table 3 8 2 Data item Bits Data type Of
84. LONASS Data End Several messages with Transport Header Transport their own transport frames n Start Message Reference Position End Transport Header Transport RNX message presents receiver data directly in RINEX 3 like manner The variety of GNSS and their signals is almost unlimited in RNX messages because it uses universal and flexible data identification Group RNX can support a number of compact data presentation options making it usable both for raw data recording and as an effective differential protocol Since ATOM RNX message allows different customization and optimization scenarios to be implemented a number of additional explanations clarifications are provided in Appendixes C D and E These Appendixes allow users to understand in more details what algorithmic background is behind RNX observation message ATOM RNX observation message can generate the following primary observables for each tracked signal RINEX definitions Pseudo range C Carrier phase L Doppler D Signal strength S Since there is still some ambiguity in interpretation the statements below clarify the definition of the observables packed into ATOM RNX messages e Time tags pseudo ranges and carrier phase for each GNSS correspond to RTCM 3 and RINEX conventions shtech e pseudo ranges and carrier phases at least for a given GNSS are supposed to be controlled by the same receiver clock e All carrier phases are matched to their respective pse
85. Message EX Ternal Bo een 130 3 7 6 ATOM DAT Messaes UNTernal receiver dala ea ee 133 ATOM DAT Message Universal GNSS raw data frames naar 133 3 8 ATOM RN UI n NIRE 135 3 8 1 Message structure and header ae en nee ee EEO E E ESENE EEE ECDAT ERESSE EEN 136 3 8 2 MON SS BCA SE e een een 142 3 8 3 Satelite Cate 145 3 6 4 SIENA ala or see N 146 3 8 5 Reterence positon ee een 148 3 8 6 Extended RINK data ee a eek 155 3 9 AES Ec een 160 310 ATOM EVT sun en a else 161 STA Messe erteilen 162 ONES NIRE MEIN IS Lec nn ee ee ee 162 4 ATOM SERIAL INTERFACE 163 41 Getting ciu gos aspen M HQ 163 4 2 Using the Extended Serial Interface for Sub Message amp Sub Block 7 nnne 164 4 3 Using the Extended Serial Interface for Observables Scenario 166 coca cie E 168 4 5 Output to viral dia ea 168 46 RNX scheduling among different 11 510
86. Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 uint10 14 Message length in bytes MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 6 is reserved for ATOM DAT message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which DAT message follows For DAT message type 9 uint9 55 0 511 this message seio MESSAGE DATA 0 GPS GNSS ID 3 uint3 64 0 7 1 SBAS ashtech 2 GLONASS 3 GALILEO 4 QZSS 5 Beidou 6 7 reserved for other GNSS Satellite ID 6 sine 67 0 63 The rank 1 in Satellite mask see DF394 in section 3 3 Signal ID 5 uints 73 0 31 The rank 1 in Signal mask see DF395 in section 3 3 Channel ID 8 uint8 78 0 255 The receiver channel number tracking given signal 0 15 GLONASS it is freq number indicator see also message STA GEN u SBAS it is time of message TOW Other GNSS set to 0 0 1 User must skip this message if the flag is set AF024 Overlap flag 1 uintl 90 to 1 See Appendix Reserved 9 bit9 91 Set to 0 0 Subframe data length K 12 uint12 100 l bit 0 4096 The number of bits in subframe data
87. Modified copy of EPH GPS RTCM 3 MT 1044 not yet signal data standardized 6 EPH BDS ephemeris from 21 RTCM 3 MT not yet signal data standardized Copy of SAL but in compact ashtech 11 ALM GPS almanac PASHR SAL presentation 12 ALM GLO almanac PASHR SAG presentation 13 ALM SBAS almanac Copy GLA WS PASHR SAW presentation 14 ALM Galileo almanac N A 15 ALM QZSS almanac Modified copy of ALM GPS N A 16 ALM BDS almanac N A 21 GPS ionosphere and time Copy of ION message butin PASHR ION shift parameters compact presentation 24 GIT Galileo ionosphere and time N A shift parameters 25 0255 ionosphere and time N A shift parameters 26 GIT BDS ionosphere and time N A shift parameters 22 GPS full time parameters 1 7 RTCM 3 1013 B GPS UTC time shift 3 61 NAV Message GPS Ephemeris This message contains GPS ephemeris data for a given GPS satellite For detailed information about GPS ephemeris data please refer to the ICD GPS 200 document Output Logic Message Binary size How to request Permissible intervals x sec on time on change on new 72 bytes 576 bits PASHS ATM NAV lt Port Name ON x amp EPH 1 2 each integer second but less than 999 See also PASHR SNV RTCM 3 Message 1019 Table 3 6 1 a Message structure and content Data item Bits Data
88. ON Table 3 6 16 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes Set to 26 for this message shtech MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 NAVinessagetype 9 ww 5 osi Speise which NAV message follows For MESSAGE DATA 00 8 int8 64 Ionospheric parameter seconds al 8 int8 72 Ionospheric parameter seconds semi circle a2 8 int8 80 2 Ionospheric parameter seconds semi circle a3 8 int8 88 27 Ionospheric parameter seconds semi circle 8 int8 96 g Ionospheric parameter seconds 8 int8 104 a Ionospheric parameter seconds semi circle 2 8 int8 112 2 6 Ionospheric parameter seconds semi circle p3 8 int8 120 27 Ionospheric parameter seconds semi circle Al 24 int24 128 279 First order terms of polynomial AO 32 int32 152 a Constant terms of polynomial Tot 8 int8 184 2 Reference time for UTC data Wnt 8 uint8 192 0 255
89. RST GNSS BLOCK DATA see GNSS mask in the message header Observables Mask 16 See Table 3 8 2a Depends on Capability Mask See Tables 3 8 2b c ATOM RNX version Cell Mask lt 64 See Table 3 8 2d Satellite Data See Table 3 8 3a Signal Data See Table 3 8 4a SECOND GNSS BLOCK DATA see GNSS mask in the message header Meanings of data packing and fields are the same for each GNSS N th GNSS BLOCK DATA see GNSS mask in the message header Meanings of data packing and fields are the same for each GNSS REFERENCE POSITION see position presentation flag in the message header Reference position See Table 3 8 5a b c shtech END TRANSPORT 24 bit Cyclic Redundancy Check CRC 24 uint24 Notes The sequence of GNSS data is fixed and always follows GNSS mask GPS gt SBAS gt GLONASS gt GALILEO gt QZSS gt BEIDOU regardless of the primary GNSS used Reference position is always last and can be presented in different forms as indicated by the Position presentation flag The Multiple message bit allows the complete GNSS data epoch including reference position to be compiled from different ATOM RNX messages tagged to the same receiver time and reference station ID Reported code carrier smoothing parameters smoothing interval and divergence free indicator are copies of SM
90. S Almanac This message contains QZSS almanac data for a particular satellite For detailed information about QZSS almanac one should refer to IS QZSS_13 E document Output Logic on time on change on new Message Binary size 36 bytes 288 bits How to request PASHS ATM NAV Port Name ON x amp ALM Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR SAL Table 3 6 11 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 ashtech Message length in bytes Set to 30 for this Message Length 10 unt10 14 message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which NAV message follows For NAV message type 9 uint9 55 0 511 Deo MESSAGE DATA Satellite PRN number original ID 193 SVPRN 5 uint5 64 0 4 corresponds to 0 ID 194 corresponds to 1 etc This 8 bit Almanac health is divided into the first 3 bits NAV Data Health sun 89 Indications and last 5 bits
91. SHS ATM NAV Port Name ON x amp ALM Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR SAG ashtech Table 3 6 8 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 anti 14 Message length in bytes Set to 24 for this message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which NAV message follows For NAV message type 9 uint9 55 0 511 this message set to 12 MESSAGE DATA SatNum 5 uint5 64 1 24 GLONASS satellite number The GLONASS Satellite Frequency Channel Number identifies the frequency of the GLONASS satellite Frequency Channel 8 uint8 69 0 indicates channel number 07 Number 1 indicates channel number 06 13 indicates channel number 6 31 indicates invalid channel number Health 1 bitl 77 Satellite Health 0 bad 1 good ashtech E 15 uint15 78 27 Eccentricity Na 11 uintl
92. Some ID values may refer to specific satellites while some ID values may be indicated as Reserved in this standard These IDs may be used in the future for other satellites and thus decoding software shall ensure that it does not skip these bits but decodes complete GNSS Satellite mask decodes corresponding observables as if they refer to known satellites but should refrain from using them unless new satellite mapping table becomes available to map corresponding ID to a specific satellite DF394 GNSS Satellite mask bit 64 If any data for satellite with ID n follows then corresponding bit bit number n is set to 1 if data for satellite with ID m do not follow then corresponding bit bit number m is set to 0 shtech The sequence of bits which specifies those GNSS signals for which there is available data in this message Each bit corresponds to particular signal observable type for given GNSS The Most Significant Bit msb or the first encoded bit corresponds to signal with ID 1 the second bit corresponds to signal with ID 2 etc And Least Significant Bit 156 or the last ecoded bit corresponds to signal with ID 32 Exact mapping of actual signal identifier in correspondence with RINEX 3 01 signal naming convention to signal mask IDs is specific for each GNSS see corresponding tables in MSM description DF395 GNSS Signal mask bit 32 for each particular GNSS Some ID values may refer to specific
93. To disable particular ATOM group on a given port use the following command PASHS ATM lt Group type gt lt Port Name gt OFF To disable all the ATOM messages on a given port use the following command PASHS ATM ALL Port Name gt OFF The existing ATOM groups can be divided into two categories those configurable by sub messages or sub blocks ALR SUP PVT ATR NAV DAT STA EVT and those configurable by scenario RNX The way ATOM messages are output is under the control of the ATOM setup Users can configure the ATOM setup using the extended serial interface described in the sections below 4 2 Using the Extended Serial Interface for Sub Message amp Sub Block Customization ATOM messages ALR SUP PVT ATR NAV DAT STA and EVT contain different sub messages sub blocks which users can choose to generate with their own period or not Sub block means a data block inserted under a message header i e generated within the same transmission together with other sub blocks Sub message means independently generated data belonging to a given group type To customize these groups the extended serial interface should be used PASHS ATM Group type gt lt Port Name gt ON Per amp mm1 mm2 mm3 Or PASHS ATM Group type gt lt Port Name gt OFF Per amp mm1 mm2 mm3 where mm1 mm2 mm3 are sub message sub group identifiers Per is the optional period in seconds Users can request sub messages sub g
94. Total 184 Table 3 4 12 b SVS header for ATOM PVT version 1 Data item Bits Data type Offset Scale Range Comments DF Number SVS HEADER Block size 8 uint8 0 0 255 Set to 19 3 Nsat 2 Ncell Block ID 4 uint4 8 0 15 Set to 14 0 GPS 1 SBAS 2 GLONASS GNSS ID 3 uint3 12 0 7 3 GALILEO 4 QZSS 5 Beidou 6 7 reserved for other GNSS Satellite mask 40 bit40 15 See Appendix E See DF394 Signal mask 24 bit24 55 See Appendix E See DF395 Cell mask 64 bit64 79 See Appendix E See DF396 Reserved 9 bit9 143 0 511 Set to 000000000 Total 152 Notes e Unlike the ATOM RNX message the size of the Cell mask is always fixed and equal to 64 bits This is to simplify the parsing of the SVS sub block Actually only the first Nsat Nsig bits in the Cell mask have sense All the remaining bits are set to zero ATOM PVT ver 1 defines Sat mask size 40 bits and Signal mask size 24 bits ATOM PVT ver 2 defines Sat mask size 64 bits and Signal mask size 32 bits The meaning of first 40 bits in Sat mask v 2 and Sat mask v 1 is the same The meaning of first 24 bits in Signal mask v 2 and Signal mask v 1 is the same Decoding equipment must analyze version number and process all the other fields accordingly ashtech If experienced size of Cell mask exceeds 64 bits e g 14 Satellites and 5 Signals i e 14 5 70 gt 64 then tracking status for given GNSS can be presented by two or more sequential SVS blocks complementary to each other Decoding equ
95. a In fact all compact data protocols e g standardized RTCM 3 observation messages are in some degree limited by admissible observations divergence For example abs L1 pseudo range L2 pseudo range must not exceed about 163 meters The diagrams below show good and bad examples of raw data Cloud of measurements s OK M M lt 327 68 2 327 68 window shtech Cloud of measurements min x 3 X X x NOT OK gt 327 68 327 68 window In case when the cloud contains outlying pseudo ranges ATOM RNX generator will remove them before packing It is full ATOM RNX generator responsibility to determine which pseudo ranges should be removed In case when the cloud contains outlying carrier phases ATOM RNX generator will reinitialize them by introducing new integer number of cycles before packing In this case ATOM generator can add subtract a priori known number of cycles 1024 cycles rollover which can be applied on decoding site to sew carrier phase data It is full ATOM RNX generator responsibility to determine which carrier phases should be corrected Similar rollover procedures exist in standardized RTCM 3 messages It must be emphasized once more that generally Rough Range is not associated with any single observable pseudo range or phase On contrary Rough Range is associated with the
96. a type Offset Scale Range Comments DF Number REFERENCE DATA 0 stationary Motion flag 1 0 0 1 1 moving 0 precise mm accuracy Position quality flag 3 uint3 1 0 7 2 RTK float dm accuracy 3 DGNSS sub meter accuracy ashtech 4 Standalone few meters accuracy 5 Rough hundreds meter accuracy 6 Approximate km level accuracy 7 unknown Reserved Bit7 0 127 Set to 0000000 Position tagging uint3 11 0 7 0 Antenna reference point 1 L1 phase center 2 5 reserved 6 Ground mark 7 Unknown X coordinate 38 int38 14 0 0001 m 13743895 347 lm 13743895 3472 if not defined or invalid DF025 Y coordinate 38 int38 52 Ditto Ditto Ditto DF026 Z coordinate 38 int38 90 Ditto Ditto Ditto DF027 Clarifier switch uint2 128 0 3 0 Extended position data follow 1 Extended time data follow 2 3 reserved Clarification data 22 bit22 130 See tables 3 8 5 d e X velocity 25 int25 152 0 0001 m s 1677 7215 1677 7216 if not defined or invalid Y velocity 25 int25 177 0 0001 m s 1677 7215 1677 7216 if not defined or invalid Z velocity 25 int25 202 0 0001 m s 1677 7215 1677 7216 if not defined or invalid Reserved 227
97. ar pseudo range e g LICA mean value of all available pseudo ranges Computed range Rough range is generated with a resolution of 1 1024 ms about 300 meters and is broken down into two components e number of integer milliseconds in rough range 8 bits covering the interval 0 to 255 ms Therough range modulo 1 millisecond 10 bits covering the interval 0 to 1023 1024 ms The receiver can generate the following Fullrough range 18 bits e Fractional rough range 10 bits e Norough range at all 0 bits ATOM RNX can generate specific terms for each observable as follows Fine pseudo range as original full pseudo range modulo 655 36 meters with a resolution of 0 02 meters 15 bits covering the interval 0 to 655 34 meters e Fractional carrier phase as original carrier phase modulo 1 cycle with a resolution of 1 256 cycles 8 bits covering the interval 0 to 255 256 cycles Integer cycle carrier phase as original carrier phase modulo 4096 cycles with a resolution of 1 cycle 12 bits covering the interval 0 to 4095 cycles If generated the integer cycle carrier phase is supplemented by the cumulative loss of continuity indicator representing a 4 bit field incremented by 1 each time the original full carrier integer ambiguity is reinitialized re computed to match the corresponding full original pseudo range The general algorithm to restore any Full observable pseudo range or carrier phase from
98. arly this message can contain incoming differential corrections and or commands used to configure the receiver Packed data are the data created by an external device that is why GNSS receiver which outputs DAT EXT messages is not responsible for their content Packed data can be of known structure and user can process them by own algorithms tools At the same time packed data can be of unknown structure in which case user must inquire which source created the original data packed into DAT EXT Output Logic on change Message Binary size depends on buffer organization How to request PASHS ATM DAT lt Port Name gt ON amp EXT Permissible intervals x sec N A See also N A Table 3 7 5 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 6 is reserved for ATOM DAT message ashtech Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which DAT message follows For DAT mes
99. ashtech ATOM Ash Tech Optimized Messaging GNSS receiver communication protocol versions 1 2 Reference Manual Revision 2 28 July 10 2013 ashtech Ashtech reserves the right to make changes to the ATOM format specification without notice REVISION HISTORY Track the revision history of the ATOM format Interface Control Document Release Date Author Comments 1 00 Jan 15 2009 Initial creation 1 01 Feb 28 Style changes misprints fixes 2009 ATOM RNX section corrected ATOM BAS section completed Appendix C modified Appendix E modified ATOM PVT TTS message description added Antenna name message meaning extended 1 02 March 31 ATOM PVT COO block modified by adding position type clarifier 2009 Invalid GNSS time tag specified ATOM DAT EXT message modified clarified ATOM ATR SNS message reserved PVT SVS block modified Azimuth and Elevation definition clarified 1 03 April 30 Defaults of ATM PVT message changed 2009 Adding serial interface to request second PVT message ATOM PVT SVS block description clarified 1 04 May 31 Definition of PRR data clarified 2009 GLONASS almanac description corrected Some re formatting of the text performed per StephaneM request Few minor changes made in Section 4 to reflect ATM HED message 1 05 October 15 Appendix E is modified in section E 5 2009 ashtech ATOM PVT PRR block is clarified ATOM RNX message finalized in part of e
100. ata Nsat times il follow See section 3 8 6 Total Notes Considering Integer number of ms in Satellite range for example repeating this field means that the value of this field will be provided in succession for each of the satellites for which the Satellite mask is 1 see Table 3 8 2b With 10 tracked satellites for example the field size will finally be 80 10x8 bits e Full rough range in ms is just the sum of the first 2 fields above In case when integer number of ms is not available it is responsibility of decoding equipment to restore it using known approximate position and available navigation data 3 8 4 Signal data ashtech Signal data have 5 optional blocks that can be inserted in the message depending on configuration bits in the Observable mask see Table 3 8 2a These blocks contain information specific to each signal In each of these 5 blocks the field s having the same meaning for each of the signals from a given GNSS are internally repeated Ncell times in order to output the value s of this or these fields for each of the signals The value of Ncell is known after decoding the Cell mask see Table 3 8 2c Table 3 8 4 a Signal data for resolution 0 standard Data item Bits Data type Offset Scale Range Comments DF Number SIGNAL DATA 15 2 Inserted if fine or full pseudo Fine pseudorange data Ncell times uintl5 Nee 0 02m 0 655 34
101. atellite can be internally recognized as unhealthy This does not generally prevent to output its observables It must be noted that Sat can be set internally unhealthy by different reasons almanac data own ephemeris data SBAS integrity data external integrity flags etc If a Sat has no ephemeris and marked as unhealthy then Status 3 is reported Table 3 8 6 b Extended Signal data if resolution 0 ashtech Data item Bits Data type Offset Scale Range Comments DF Number EXTENDED SIGNAL DATA one Signal portion Channel number 8 unt8 0 0 255 Value 0 means not defined Fine Doppler 15 int15 8 0 0001 m s i a Value 1 6384 means invalid To be added to pseudo range to get unsmoothed value The copy of MPC smooth correction but with 2 opposite sign Smoothing residual 11 intl1 23 0 02 m 20 46 m Value 20 48 means invalid Value 20 46 means less or equal 20 46 value 20 46 means more or equal 20 46 The copy of smooth count Smooth count 8 uint8 34 1 sec 0 255 Value 255 means 255 Br Original channel warnings see Signal warnings 14 bit14 42 table 3 8 64 Total 56 Table 3 8 6 Extended Signal data if resolution 1 Data item Bits Data type Offset Scale Range Comments DF Number EXTENDED SIGNAL DATA one Signal portion Channel number 8 uint8 0 0 255 Value 0 means not defined Fine Doppler 15 int15 8 0 0001 m s ea Value 1 6384 means invalid Smoo
102. c interval is selected for the RNX and PVT groups GPS is the primary GNSS used and the GPS UTC time shift is 15 sec as from January 1 2009 until June 30 2012 then RNX and PVT will always be output for different time tags Fach even second of GPS time tag will contain data Each odd second of GPS time tag or each even second of UTC time tag will contain PVT data Some ATOM messages being requested will be generated regardless their content is valid or not E g ATM PVT COO data will be generated if receiver cannot compute position or computed position is internally recognized as invalid In this case position components will take pre specified invalid value at the same time other fields in still can report valid values On contrary some other ATOM messages being requested can stop outputting if their content is invalid or no longer actual Say a particular NAV message e g EPH with expired age of validity is not output Or messages of STA group e g differential decoder status stop outputting in case their content was not updated during some time 3 2 Data Field Conventions Each of the binary Data Fields DF described below fits one of the types presented in the following table Data type Description Range Example Notes bitX Bit field each bit is O or 1 0 1 bit2 2 bit field X is the length of the bit field gt bit11 11 bit field ashtech ui
103. ceiver shtech 3 3 Satellite Signal and Cell Masks information is moved to endix Satellite Signal and Cell Masks ashtech 3 4 ATOM PVT Message ATOM PVT Position Velocity Time outputs receiver positioning results It can generate all valuable data contained in the existing standardized NMEA e g GGA GSV GST and proprietary Ashtech e g PBN POS SAT messages The PVT message is not a group of separated messages but a solid generic message containing a number of sub block data Some sub blocks have fixed length some others have variable length Besides there can be more than one PVT message corresponding to the same epoch time The ATOM PVT message with its default set of sub blocks and intervals can be enabled disabled using the following command PASHS ATM PVT lt Port Name gt ON OFF The general organization of the PVT message is presented on Figure 3 4 a Start Message Sub Block 1 Sub Block 2 Sub Block N End Transport Header Data Data Data Transport 3 bytes 10 bytes 3 bytes Figure 3 4 a PVT message organization The table below sketches the ATOM PVT message and presents the organization of its header Table 3 4 a PVT header organization Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 Bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in by
104. cloud of observables for given Satellite And reported Rought Range 1 1024 ms resolution is not actually computed as round off of some float value on contrary it is selected among up to several admissible candidates Let integer N be the number of 1 1024 ms intervals in Rough Range Typically it is in the range 60000 80000 except SBAS QZSS and similar systems with exclusive orbits There exists the only single limitation when selecting N value for packing Vi IMi N Const lt 327 68 m Const 292 76607226562498 m In theory there can be up to 3 different N values depending on cloud size and location The diagrams below show all possible cases Single valid N Cloud of measurements m e gt 327 68 lt lt 327 68 Mmin Two valid N shtech shtech Cloud of measurements gt 327 68 EY d lt 327 68 m Mmin Three valid N shtech Cloud of wv Mmax measurements m gt 327 68 v lt 327 68 m With multiple N opportunity IT DOES NOT MATTER which N ATOM generator selects If the cloud of Sat data to be packed does not fit favorite conditions then ATOM generator can e Split transmission by Signals and use multiple generation or Do not generate outlier data at all Generate all the data still by modulo 327 68 meters and provide extra indication in extended supplementary data Depending on ha
105. column of this rectangular table corresponds to Satellite with smallest ID among those for which corresponding bit in Satellite Mask is set to 1 The second column corresponds to the Satellite with the second smallest ID among those for which corresponding bit in Satellite Mask is set to 1 The last column corresponds to the Satellite with the highest ID among those for which corresponding bit in Satellite Mask is set to 1 If observable data for given Satellite and given Signal follows then corresponding field in this table is set to 1 otherwise it is set to 0 This bit table is packed by columns starting from the column which corresponds to smallest Satellite ID The size of each column is Nsig bits and it is packed starting from the cell which corresponds to the smallest Signal ID ashtech Each cell of the table is packed by one bit which is set to 1 or 0 according to the value in the corresponding cell in the table Examples to construct and interpret given masks are given in Appendix E The table below gives an overview of GNSS signals currently supported by ATOM Potentially ATOM can support all known existing and incoming GNSS signals The number of supported signals can be up to 32 for each GNSS All carriers corresponding to different signals of the same band are aligned to each other by proper usually 0 25 fractional part of cycles Reference Signal for Phase Alignment Frequency Fr
106. combination 4 Dual band SNR pseudo range and carrier phase in full presentation extended The generalized analog of RTCM 3 MT 1004 1012 1006 fixed position follows each 12 epochs Can support L1 amp L2 as well as L1 amp L5 or any other dual band combination Compact differential protocols 100 Dual band compact pseudo range and full carrier phase extended fixed Can support L1 amp L2 as well as L1 amp L5 or any other dual band combination position follows each 12 epochs all the data are decimated in 5 times By default pilot carrier is L1 compared to a pilot carrier phase 101 Dual band compact pseudo range and compact carrier phase extended fixed Can support L1 amp L2 as well as L1 amp L5 or any other dual band combination position follows each 12 epochs all the data are decimated in 5 times By default pilot carrier is L1 compared to a pilot carrier phase This scenario cannot be used with moving receiver Differential protocols for moving base 201 Same as scenario 1 but extended computed reference position follows each epoch 202 Same as scenario 2 but extended computed reference position follows each epoch 203 Same as scenario 3 but extended computed reference position follows each epoch 204 Same as scenario 4 but extended computed reference position follows each ashtech epoch 300 Same as scenario 100 but extended computed reference position follows each epoch Notes Receiver port scenario
107. cters describe occupation name Occupation description 8 uint8 0 255 N umber of characters in occupation counter M description field Occupation description 8 M char M pane icd see occupation description END TRANSPORT ashtech CRC 24 uint24 24 bit Cyclic Redundancy Check CRC Total 3 57 ATOM ATR Message External Sensors Data 3 5 8 ATR Message Meteo Data This message contains information about local in reasonable vicinity of GNSS antenna meteo parameters allowing mitigating troposphere error It is supposed that given message can be generated together with other attributive information receiver antenna names from base to rover with not so high speed It can be also used as a source of RINEX meteo file It is supposed that given meteo information is either automatically available at the MET message generator meteo sensors streams it reading to MET generator or local meteo parameters are entered receiver on some regular basis via available serial interface The meteo data generated in SNS and MET messages are the same Output Logic on new on change Message Binary size 142 bits 18 bytes How to request PASHS ATM ATR Port Name ON amp MET Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also GPXDR Table 3 5 8 a Message structure and content
108. cument Output Logic on time on change on new Message Binary size 56 bytes 448 bits How to request PASHS ATM NAV lt Port Name gt ON x amp EPH Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR SNG RTCM 3 Message 1020 Table 3 6 2 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unti 14 Message length in bytes Set to 50 for this message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 message type 9 9 55 0 511 Specifies which NAV message follows For this message set to 2 MESSAGE DATA If 1020 then all the data below exactly Standardized message 12 int 64 correspond to standardized RTCM message number 1020 see official RTCM 3 If 0 then shaded fields are declared as reserved and ashtech can take arbitrary values SatNum 6 uint6 76 1 24 Satellite number DF038 The GLONASS Satellite Frequency DF040 Channel Number identifies the frequency of the GLONASS
109. d serial number RTCM 3 MT 1008 RNM Be Name firmware version and serial RTCM 3 MT 1033 receiver s part number 3 ANM Physical antenna name Name setup ID and serial number RTCM 3 MT 1008 5 UEM User entered message RTCM 3 MT 1029 6 RIO Receiver Installed Options Receiver options PASHR RIO 7 GNSS configuration receiver Signals receiver can potentially PASHR CFG supports track The reported values allows RTCM 3 MT 1230 8 CPB adjusting Ashtech raw data to value golden standard Slant radius vertical offset PASHR ANT ANH 21 Antenna offset parameters horizontal offset horizontal offset RTCM 3 MT 1006 angle 23 Site occupation information Dynamic index site name start stop N A ashtech etc 24 SNS Non GNSS sensor data Weather and other parameters GPXDR 25 Meteo data Primary weather parameters GPXDR Sensor type name model position PASHR RXC PAR 27 SAH can be used instead of block SNS sensor data 24 Notes observables generated in the ATOM MES RNX and BAS messages always correspond to antenna name specified in message type 1 At the same time this name can correspond to either a physical antenna e g MAG990596 or a virtual antenna e g ADVNULLANTENNA for which raw receiver data can be optionally adjusted before being output In the latter case the receiver can additionally generate ATR messa
110. dReference Find how far restored range from Rough part if dDelta gt fAmbiguity 2 dFullRange fAmbiguity make minus correction else if dDelta fAmbiguity 2 dFullRange fAmbiguity make plus correction shtech Appendix D Decimation for ATOM RNX observables The idea of decimation is well known It comes from the simple fact that the dynamic of all the basic observables pseudo ranges and carrier phases corresponding to a given satellite is almost the same Their divergence due to the ionosphere and some other factors is usually a slow process This means that having acquired only one precise observable e g L1 carrier phase for all the epochs allows the observables that are missing at some epochs to be restored Decimation for ATOM observations refers to a special scenario in which all the data except the L1 carrier phase are generated at a slower rate For example with the L1 carrier phase generated at 1 second the L2 carrier phase L1 and L2 pseudo ranges can be generated with a 5 sec interval resulting in 5 times decimation On decoder side the decimated data can be easily restored provided the continuous tracking of the L1 carrier phase is achieved Restoring pseudo ranges is trivial even for 10 to 30 seconds decimation Restoring a decimated L2 or L5 carrier is different as a second order estimator has to be applied to more precisely eliminate ionosphere divergence In all cases the rover must monitor the cont
111. defined This is because not all PVT engines can provide information for these fields The position type clarifier AF003 is provided to specify in more details what is behind the standardized GGA type position flag e g to distinguish between DGNSS and DSBAS All DOPs figures are computed assuming independent clock offset for each GNSS i e in case of 3 GNSS systems used GPS GLONASS GALILEO matrix is 6x6 matrix Reported Differential position age refers to the difference between current time tag and the time tag to which applied original differential corrections are tagged i e correction project time Please note that last received corrections in some cases can be not applied So growing of differential position age does not always mean data link stop but indicates the degree of position degradation On contrary Differential link age refers to the difference between current time tag and the time tag to which latest decoded corrections are tagged to So growing differential link age does mean failure on base or in communication Position is reported as Cartesian position Geodetic position can be computed by user applying proper ellipsoid parameters The datum bit default or custom is provided in MIS block If datum is default then user must apply corresponding default ellipsoid parameters unique for GNSS specified as primary If datum is custom then its name and ellipsoid parameters are available via additional CDC c
112. e GST is TBD GALILEO IODnav 10 uint10 94 1 0 1023 Issue of data unitless DF290 GALILEO SV SISA 8 uint8 104 SIS Accuracy data content definition not DF291 SIS Accuracy 0 given in GALILEO OS SIS ICD reserved 14 int14 112 gs See Note 1 Rate of inclination Unit semi circles s DF292 GALILEO 1 IDOT GALILEO toc 14 uint14 60 983 040 Clock reference time Unit semi DF293 126 circles sec The start time for Galileo System Time GST is TBD GALILEO a 6 int6 140 27 See Note 1 Clock correction Unit s s DF294 GALILEO 21 int21 146 3 See Note 1 Clock correction Unit s s DF295 ashtech GALILEO 31 int31 167 27 See Note 1 Clock correction Unit seconds DF296 GALILEO 16 int16 198 gs See Note 1 Amplitude of the sine harmonic correction DF297 term to the orbit radius Unit meters GALILEO An 16 int16 y See Note 1 Mean motion difference from computed DF298 214 value Unit semi circles s GALILEO Mo 32 int32 230 gal See Note 1 Mean anomaly at reference time Unit DF299 semi circles GALILEO Cw 16 int16 a See 1 Amplitude of the cosine harmonic DF300 262 correction term to the argument of latitude Unit radians GALILEO e 32 uint32 278 TT 0 03 Eccentricity unitless DF301 GALILEO 16 intl6 See Note 1 Amplitude of the sine harmonic correction DF302 310 term to the argument of latitude Unit
113. e 1019 Table 3 6 5 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unti 14 Message length in bytes Set to 66 for this message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 message type 9 9 55 0 511 Specifies which NAV message follows For this message set to 5 MESSAGE DATA Reserved 12 uint12 64 Set to 0 0 1 5 Satellite PRN number original ID 193 di corresponds to 1 194 corresponds to 2 etc ashtech Wn 10 uint1O 82 0 1023 GPS week number DF076 Accuracy 4 uint4 92 User range accuracy DF077 Code on L2 2 bit2 96 10 C A code ON fixed value DF078 Idot 14 int14 98 Rate of inclination semicircles sec DF079 Iode 8 uint8 112 Orbit data issue DFO71 Toc 16 uint16 120 16 Clock data reference time sec DF081 af2 8 11 8 136 gros Clock correction sec sec DF082 afl 16 int16 144 pe Clock correction sec sec
114. e finalized 2 13 January 30 Galileo EPH message updated to match final RTCM 3 1045 changes 2012 The definition of cycle slip counter for ATM RNX is clarified Note about invalid data generation added to Section 3 1 2 14 February Galileo almanac message added to NAV group 28 2012 Galileo ephemeris message updated Message STA GEN modified Message STA BLA modified Reference documents list updated Note to section C 2 added 2 15 March 31 Misprint int16 uint16 corrected for field E in ATM NAV ALM GPS 2012 Galileo almanac message modified Choice QZSS added to GNSS masks 2 16 April 30 PVT message edited 2012 New block for ATOM PVT is reserved LMP Section 2 4 is added with short overview of multiple ATOM PVT output ushtech Section 4 9 added with additional serial interface in case of advanced PVT modes Field AF020 clarified Field AF023 reserved 2 17 June 30 New block for ATOM PVT is created LMP 2012 Extra notes added to section 2 4 about local positions projections QZSS Sat and Signals ID description added Message ATM ATR CPB created Message ATM DAT FRM finalized Some CQ entries addressed QZSS ephemeris message added QZSS almanac message added 2 18 July 24 Galileo Almanac message updated 2012 Message ATR CPB updated Mentioning of MES and BAS completely removed ATM PVT PRR block updated Extended ATM PVT blocks local coordinates updated 2 19 15 Additional possibili
115. e groups of messages 2 4 An example of ATOM PVT architecture A closer look at the organization of the ATOM PVT message for example shows that it starts with a 10 byte header containing the following data for exact presentation please refer to the dedicated section Field Comment Message number 111111111111 4095 reserved for Ashtech Message sub number 001123 reserved for PVT Message version 001 1 refers to the first version of the ATOM PVT message 1 indicates that more 4095 3 message s will follow for the same time tag 0 indicates that it is the last message tagged to a given time tag Number of satellites Number of GNSS satellites visible tracked used in position Primary GNSS system Defines the meaning of time tag and position datum Time tag Presentation depends on primary GNSS system Reserved bits For future use Note that multiple GNSS receivers make an assumption about the primary GNSS system used default is usually GPS When a primary GNSS system is specified then the ATOM message time tag and position datum refer to that primary system Currently the following primary PVT data sub blocks are supported Block type Block ID Size in bytes Position 26 Accuracy ERR 10 Velocity VEL 12 Clock CLC 10 Latency LCY 3 Attitude HPR 11 Baseline BLN 16 Miscellaneous MIS 23 shtech
116. eceiver using below reported values Reserved 3 bit3 65 Set to 000 GLONASS LICA bias follows DF422 GLONASS signals 4 bit4 68 Bit2 GLONASS LIP bias follows bitset i Bit3 GLONASS L2CA bias follows Bit4 GLONASS L2P bias follows GLONASS biases are packed only for DF 423 426 GLONASS bias for up signals having 1 in corresponding positions to 4 signals us ae 2 W 65534 of GLONASS signal bitset Invalid values ashtech END TRANSPORT CRC 24 uint24 24 bit Cyclic Redundancy Check CRC Total 3 6 ATOM NAV M ashtech Messages of the NAV NAVigation data group contain selected information which can be extracted from GPS GLONASS SBAS QZSS GALILEO and other navigation signals All these messages can be requested independently of each other Messages EPH and ALM are requested by the same command regardless of the GNSS they pertain to Only one NAV message can be output over any given 1 interval The set of default ATOM NAV messages with default intervals can be enabled disabled using the following command Port Name gt ON OFF The general organization of the NAV message is presented on Figure 3 6 a and in Table 3 6 a Start Message Message Data Transport Header Transport 3 E 5 ro 3 bytes Figure 3 6 a NAV messages organization Table 3 6 a NAV messages organization
117. econd 0 3592 invalid time 1 fine time tag extension follows Dus extension pe 1 m 0 full time tag extension follows ren 8 13 Primary time tag extension see table below Total 21 Table 3 4 c FULL Time tag presentation Data item Bits Data type Offset Scale Range Comments DF Number ashtech Hour 5 uint5 0 1 hour 0 23 GNSS hour within GNSS day Set to GPS day 0 6 within GPS week 0 is Sunday 1 is Monday etc Set to GLONASS day 0 6 within GLONASS week 0 is Sunday 1 is Monday Day 3 uint3 5 1 day 0 7 etc Se to BDS day 0 6 within BDS week 0 is Sunday 1 is Monday etc In each case 7 refers to unknown day Total 8 Table 3 4 d FINE Time tag presentation Data item Bits Data type Offset Scale Range Comments DF Number Fractional second 8 uint8 0 5ms 0 995 GNSS time modulo 1 sec Total 8 Notes time tag always refers to the time scale of the primary GNSS system used i e UTC where Nls is the number of leap seconds i e 15 as from Jan 1 2009 and 16 as from July 1 2012 for GPS and UTC 3 hours for GLONASS e size of the time tag is always fixed Using the switchable time tag presentation users can cover a full range of GNSS time tags with fine resolution If the time tag is an integer second the generator w
118. ed 16 int16 28 0 01d s 327 67 d s 327 68 means invalid Roll speed 16 int16 44 0 01d s 327 67 d s 327 68 means invalid Heading rms error 10 uint1O 60 0 01d e 10 23 means invalid Pitch rms error 10 uint10 70 0 01 d eee 10 23 means invalid Roll rms error 10 uint10 80 0 01 d en 10 23 means invalid 0 means time tagged estimates Extrapolation interval 10 uintl1O 90 10 ms 0 10230 ms 10230 means 102304 Reserved 4 bit4 100 See Appendix G AF017 Total 104 Note e Sign conventions for angular speed needs to be specified e Accuracy reported as 0 zero does not mean invalid estimate For example if heading is estimated by very long baseline e g gt 100 meters then actual accuracy can be much better than used resolution So reported zero accuracy actually tells that it is between 0 and 0 01 degree rms e Extrapolation interval is considered as true even if associated angles and their derivatives are reported as invalid ashtech This sub block contains supplementary information to BLN sub block such as baseline change rate baseline accuracy and some other valuable indicators User can request it 3 4 10 ATOM PVT Message Sub Block Baseline Supplementary Data additionally if BLN information is not sufficient for his her application Output Logic Sub block Binary size How to request Permissible intervals x sec on time 19 bytes 152 bits PASHS ATM PVT lt Port Name gt ON x amp BSD 0 0
119. ed with more than single PVT message each responsible for particular GNSS solution Thanks for generic structure of PVT message these multiple PVT output can be decoded by the same parser but receiving entity must interpret these multiple PVT messages correctly To do this ATOM PVT generator provides special identifying information inside ATOM PVT header so called Request ID 2 5 An overview of ATOM RNX observation message It contains blocks of GPS GLONASS etc observables as well as optional reference position static or moving Presentation of observables is exactly the same for each GNSS This allows the same source code to be used to construct and parse each GNSS observation block Each of these blocks can be transmitted inside a single message or can be spread among several transmissions as shown below In latter case decoding equipment must process Multiple Message Bit available in the header of each observation message properly It must be also noted that in some specific cases e g when the number of tracked Signals is too high the observation data for a single GNSS can be also spread among several sequential transmissions in this case Multiple Message Bit is also set to allow complete epoch compiling Start Message GPS Data GLONASS Data Reference End Transport Header Pasion Transport One transport frame several information blocks inside ashtech Start Message GPS Data End Transport Header Transport Start Message G
120. em Bits Data type Offset Scale Range Comments DF Number REFERENCE POSITION Motion flag 1 0 0 1 1 moving 0 precise mm accuracy 1 RTK fixed cm accuracy 2 RTK float dm accuracy 3 DGNSS sub meter accuracy 4 Standalone few meters Position quality flag 3 uint3 1 0 7 5 Rough hundreds meter accuracy 6 Approximate km level accuracy 7 unknown ashtech Reserved 7 bit7 4 0 127 Set to 0000000 0 Antenna reference point 1 L1 phase center Position tagging 3 uint3 11 0 7 2 5 reserved 6 Ground mark 7 Unknown X coordinate 38 int38 14 0 0001 m invalid 471 m Y coordinate 38 int38 52 Ditto Ditto Ditto DF026 Z coordinate 38 int38 90 Ditto Ditto Ditto DF027 0 Extended position data follow Clarifier switch 2 uint2 128 0 3 1 Extended time data follow 2 3 reserved Clarification data 22 bit22 130 See tables 3 8 5 d e Total 152 Notes The Clarifier switch allows the different clarification data provided in the next 22 bits to be used For example a typical transmission scenario can be as follows In one epoch of reference position data antenna height and ITRF epoch year are generated In the next epoch of reference position data GPS UTC time offset and GPS week number are generated Table 3 8 5 c Compact reference position clarification data velocity amp clock Data item Bits Dat
121. en block in bytes including Block size X uint8 0 0 255 this field Block ID 4 uint4 8 0 14 Reserved for general purpose data Sub block data 12 Each of blocks 0 14 Total 8 X Table 3 4 0 Presentation of special PVT sub blocks Data item Bits Data type Offset Scale Range Comments DF Number SPECIAL SUB BLOCK DATA The size of given block in bytes including Block size X 8 uint8 0 0 255 this field ashtech Block ID 4 uint4 8 15 Reserved for a variety of special data Special block sub ID 8 uint8 12 0 255 Special data block ID Special sub block data 20 Each of blocks 15 0 255 Total 8 X The next sections present the structure of each of the currently supported sub blocks in the ATOM PVT message Each PVT sub block is described independently of each other It is supposed that generally more than one sub block can follow the ATOM PVT header ashtech This sub block contains the most valuable information about computed position Usually the position refers to the default datum of the primary GNSS system specified in the ATOM PVT header But ATOM is open to outputting position on a custom datum Some additional not operative yet position information can be sent through the Miscellaneous MIS sub block but at a lower rate 3 4 1 ATOM PVT Message Sub Block Position message Output Logic on time Sub block Binary size 26 bytes 208 bits How to request PASHS ATM PVT
122. ent Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Set to 10 Block ID 4 uint4 8 0 15 Set to 2 Sigma 20 uint20 12 0 001 m 0 1048 574 m 1048 575 if not defined or invalid kl 7 uint7 32 1 128 0 1 Have meaning only if Sigma is valid k2 7 uint7 39 1 128 0 1 ditto k3 7 uint7 46 1 128 0 1 ditto 112 8 int8 53 1 128 1 1 ditto r13 8 int8 61 1 128 1 1 ditto shtech 123 8 int8 69 1 128 1 1 ditto Reserved 3 bit3 77 0 7 See Appendix G AF021 Total 80 Notes e If Sigma is set to an invalid value then all other fields in this sub block are also invalid and can take arbitrary values e Sigma Js11 s22 533 meter kl k2 Me k3 see all unitless sigma sigma sigma We 512 513 523 4 5 r232 all square unitless s1l 522 s11 533 4 522 533 Reported covariance matrix needs not any additional scaling because reports actual 1sigma accuracy figures E g random variable ratiol errl sqrt s11 should theoretically follow Gaussian 0 1 distribution ashtech 3 43 PVT Message Sub Block Velocity message This sub block contains receiver velocity components Output Logic on time Sub block Binary size 12 bytes 96 bits How to request PASHS ATM PVT Port Name ON
123. eous Bee een 198 Appendix H The summary 1 2 differences ne een 198 HA Satellite and Signal Masks m ATONLPVT SVS blacH sn 198 H 2 Satellite and Signal Masks in ATOM RNX GNSS observables 198 H 3 Extended data resolution in ATOM RNX GNSS observables block eee nine essen eterna nnn nennen 198 Appendix I Satellite Signal and ell Masks SNR REIR ER nM DM MIN uU nda ed M ME MEN 200 Appendix J Example of masking table for a particular 208 shtech 1 WHAT IS ATOM AND WHAT CAN IT DO Ashtech has developed its own proprietary binary data format named AshTech Optimized Messaging ATOM acronym for short to adapt to the new GNSS reality and meet all user requirements The name emphasizes the main distinguishing ATOM feature which is its ability to present data in compact form ATOM is open to further extensions with new messages or updates for already existing messages the ATOM version number is provided for each message Not all the ATOM fields need to be aligned by integer bytes boundaries However for extra convenience some fields have been grouped together to fit the integer number of bytes The key features of ATOM include Delivering the widest variety of GNSS data at any
124. equency Reference Signal RINEX Observation Band MHz Code System Ll 1575 42 L2 1227 60 15 1176 45 GLONASS Gl 1602 k 9 16 G2 1246 k 7 16 GALILEO El 1575 42 ESA 1176 45 5 1207 140 E5 A B 1191 795 E6 1278 75 L1 1575 42 L5 1176 45 L1 1575 42 L2 1227 60 L5 1176 45 Bl 1561 098 B2 1207 140 B3 1268 52 ashtech The tables below show the exact content of Satellite and Signal masks for each supported GNSS Please take a note that some positions in Signal mask are reserved for unknown Signal on particular band Such an indication allows transferring data from legacy protocols containing no signal ID or proprietary signal ID to ATOM GPS Satellite ID mapping Satellite ID in Satellite Mask DF394 GPS Satellite PRN 1 1 2 2 63 63 64 Reserved GPS Signal ID mapping Signal IDin Frequency Signal GPS signal Comments Notes Signal Mask Band RINEX DF395 code 1 Reserved 2 11 1 3 11 1 4 11 Z tracking IW 5 7 Reserved 8 L2 C A 2C 9 L2 P 2P 10 L2 Z tracking or 2W similar 11 14 Reserved 15 L2 L2C M 25 16 12 L2C L 2L 17 L2 L2C M L 2X 18 21 Reserved SignalIDin Frequency Signal GPS signal Comments Notes Signal Mask Band RINEX DF395 code 22 L5 I 51 23 15 Q 5Q 24 L5
125. eration of extended satellite and signal data is controlled by the supplementary follow field in the GNSS header 3 8 6 Extended ATOM RNX data Table 3 6 6 a Extended Satellite data Data item Bits Data type Offset Scale Range Comments DF Number EXTENDED SATELLITE DATA one Satellite portion Azimuth 8 uint8 0 2 degrees 0 358 gt 358 means invalid azimuth 0 90 means true positive elevation 91 means true elevation 1 degree 92 means true elevation 2 degree Elevation 7 uint7 8 1 degree etc 126 means true elevation less or equal to 36 degree 127 means invalid elevation Rough Doppler 14 intl4 15 1 m s 8191 m s Value 8192 means invalid DF399 0 Full Sat range available Full range available 1 bitl 29 0 1 1 No full Sat range available 0 Sat is used in position 1 Satis not used no ephemeris Satellite status 2 uint2 30 0 3 2 Sar ena other cause 3 Sat is not used unhealthy Total 32 Notes No Full Sat range available means that the original receiver pseudo range contains an unknown integer number of milliseconds but pseudo range is still valid modulo 1 ms satellite is considered as used in internal receiver position if at least one satellite observable code carrier or Doppler was used in position computation A satellite not used in internal receiver position does not imply that its observables are bad S
126. essages is one second while the nominal interval between NAV messages with fixed content is x seconds e g 600 If the specified interval x is too short to allow all requested NAV messages to be output one message per second within this interval then x will be set internally as low as necessary to satisfy the output strategy The x interval between messages cannot be chosen arbitrarily For fast messages only the following intervals are valid 0 05 0 1 0 2 0 5 sec If a receiver supports higher update rates then intervals 0 02 sec 50 Hz 0 01 sec 100 Hz and 0 005 sec 200 Hz are also admissible The phase of fast messages is chosen in order to acquire integer seconds of primary GNSS time For slow messages any integer second interval is admissible provided it is less than 999 sec However for the RNX group only the following intervals are supported 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute of primary GNSS time provided it is less than 15 minutes The phase of these messages is chosen in order to acquire integer minutes of primary GNSS time These intervals and shifts are recommended in RTCM 2 standard and are kept in mind for all the other standards Messages of the PVT group support the same intervals as the RNX group But in case of integer second intervals the phase of PVT messages is chosen in order to acquire integer minutes of UTC and not primary GNSS time Assuming a 2 se
127. et be The sixth Sub BITSET tells us that satellite 15 provides signals 2 15 shtech 8 The seventh Sub BITSET tells us that satellite 32 provides signals 2 4 10 15 as The main feature of messages is their scalability i e possibility to configure them to save message sizing lot of different configurations be generated using the following options see Section 5 3 Appendix F e Shape e Optimization Decimation Size optimized configurations can be needed for compact raw data recording However in most cases optimization is applied to reference data generation RTK base mode to allow the use of low band data links or to save throughput in traffic paid links e g GPRS Consider below one typical case of reference data generation Observables generated at 1 Hz Reference position is not generated The number of GPS GLONASS satellites is 20 12 8 SBAS is not generated The throughput estimates for the following 3 different constellations are provided in the table below GPS GLONASS LI L2 data e GPS L1 L2 data e GPS GLONASSLI data Throughput includes transport layer as well In the case of ATOM it is assumed that the basic RTCM 3 transport is used Protocol scenario Mean throughput for GPS GLO Mean throughput for GPS GLO Mean throughput for GPS L1 L2 Comments L1 L2 bytes sec L1 L1CA only bytes sec bytes sec Ashtech legacy 108 20 2160 50 20
128. et to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which message follows For message type 9 uint9 55 0 511 ashtech MESSAGE DATA a0 8 int8 64 299 Ionospheric parameter seconds al 8 int8 72 Ionospheric parameter seconds semi circle a2 8 int8 80 ges Ionospheric parameter seconds semi circle 03 8 int8 88 g Ionospheric parameter seconds semi circle po 8 int8 96 2 Ionospheric parameter seconds p1 8 int8 104 gs Ionospheric parameter seconds semi circle pa 8 int8 112 3 Ionospheric parameter seconds semi circle p3 8 int8 120 29 Ionospheric parameter seconds semi circle AO GPS 14 int14 128 0 1 Const terms clock bias relative to GPS ns 1 GPS 16 int16 142 0 1 First order clock bias relative to GPS ns s Gal 14 int14 158 0 1 Const terms clock bias relative to Gal ns Al Gal 16 int16 172 0 1 First order clock bias relative to Gal ns s A0 GLO 14 int14 188 0 1 Const terms clock bias relative to GLO ns GLO 16 int16 202 0 1 First order clock bias relative to GLO ns s AtLS 8 int8 218 BDS UTC differences at reference time ALLSF 8 int 226 Delta time between BDS and UTC after correction WnLSF 8 uini 234 0 255 22 leap second AO 32 int32 242 a Const terms clock bias relative to UTC s Al 24 int24 274 27 First order clock bias relative to UTC s s DN 8 uint8
129. f GLONASS satellite If this data DF130 GLONASS M M 2 bit2 343 field contains 01 the satellite is GLONASS M Availability of 1 bitl 345 See DF131 field description in official DF131 additional data RTCM 3 documents GLONASS calendar number of day within DF132 N 11 uintl1 346 1 day the four year period to which is referenced Te 32 intS32 357 2 Difference between GLONASS system time DF133 o ashtech DF134 GLONASS four year interval number GLONASS M 5 uint5 389 interval starting from 1996 31 Correction to GPS system time relative to DF135 GLONASS M Tops 22 intS22 394 2 GLONASS system time GLONASS M 1 GLONASS M 1 word extracted from fifth DF136 1 bitl 416 5 string string of the subframe Reserved 7 bit7 417 Set to 0000000 END TRANSPORT CRC 24 uint24 424 24 bit Cyclic Redundancy Check CRC Total 448 Notes The 12 bit standardized message number is used in this message as a switch taking the value 1020 or 0 It was created to ensure backward compatibility with legacy Ashtech messages SNG which do not contain some important fields e intS data type refers to a sign magnitude value Sign magnitude representation records number s sign and magnitude MSB is 0 for positive numbers and 1 for negative numbers The rest of the bits represents the number s magnitude For example for 8 bit
130. fset Scale Range Comments DF Number CAPABILITY MASK Satellite mask 40 bit64 0 See Appendix E See DF394 Signal mask 24 bit24 40 See Appendix E SEDEN Reserved 8 bit32 64 Set to 00000000 Total 1 2 Table 3 8 2 d mask inserted if Data ID follow 1 observable mask see Table 3 8 2a Data item Bits Data type Offset Scale Range Comments DF Number CELL MASK Cell mask a Nas See Appendix Bee Nsig Total X lt 64 Notes shtech Bit Resolution in Observable mask is hardcoded to 0 for ATOM 1 but can take values 0 and 1 for 2 Depending on this bit the presentation of Signal data can be different See Section 3 8 4 The Cell mask is of float size but its size is known after decoding the capability mask see Table 3 8 2b c Nsat is the number of tracked satellites the number of 1 s in Satellite mask Nsig is the number of available signals the number of 175 in Signal mask The ATOM generator checks X and if it is actually 264 then ATOM RNX data are to be split into more than one transmission in which case the Multiple message bit in the ATOM RNX header is set accordingly see table 3 8 1a The availability of the Data ID change counter allows the decimation of the Capability and Cell masks to be applied For some epochs observations can come without identification information In this case the previously decoded identification information can be used provided the Data ID cha
131. ge type 3 indicating the physical antenna name If the antenna names specified in ATR message types 1 and 3 are the same this means that no receiver raw data was adjusted to a virtual antenna If the antenna names in ATR message types 1 and 3 are different this means that receiver raw data corresponding to ATR message type 3 were adjusted to the virtual antenna specified in ATR message type 1 Both ATR messages type 1 and type 3 are requested through the same serial command When processing ATOM MES and BAS data these should be corrected using the PCO table corresponding to the antenna name presented in ATR message type 1 message type 3 is only informative While SNS message is primarily used for recording to the file for further post processing MET message being compact can be generated inside differential stream to inform real time rover about meteo conditions on base allowing thereby mitigating residual troposphere error 3 5 2 ATR Message Antenna attributes This message contains antenna attributes The generated ATOM observables MES RNX and BAS correspond to this antenna The content of this message is a copy of standardized RTCM 3 Message Type 1008 Output Logic Message Binary size How to request Permissible intervals x sec on time depends on message content PASHS ATM ATR lt Port Name ON x amp ANM 1 2 3 etc each integer second but less than 999 See also PASHS
132. hem these changes should not hurt anyone However in some cases newly introduced fields can play a vital role in the interpretation of other ATOM fields In this case the version number of the corresponding ATOM message will be increased and the corresponding Manual update or Amendment will be issued Some ATOM fields contain reserved states e g supplementary follow field in RNX which contains one reserved state ATOM ver 1 2 does not generate these states but new ATOM versions could If a newly introduced state can play a vital role in parsing ATOM data then the version number of the corresponding ATOM message will be increased and the corresponding Manual update or Amendment will be issued Some ATOM fields reserve one state to indicate an invalid value e g invalid carrier phase At the same time some supplementary fields e g corresponding SNR can be still valid Also on rare occasions some supplementary fields can take arbitrary values if the primary field is indicated as invalid In all these cases the decoding equipment should process correctly i e ignore invalid fields and be careful with the interpretation of the corresponding supplementary fields In almost all the messages ATOM generates field DF003 reference station ID This is the correct name if a receiver is used as reference station However if a receiver is not used as a reference station DF003 field is still used as generalized indicator for a re
133. htech This message contains receiver attributes It is a copy of standardized message Type 1033 receiver part only Output Logic on time Message Binary size depends on message content How to request PASHS ATM ATR lt Port Name gt ON x amp RNM Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHS RCP OWN RTCM 3 MT 1033 Table 3 5 3 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 4 is reserved for ATOM ATR message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 ATR message type 9 9 55 0 511 Specifies which ATR message follows For this message set to 2 MESSAGE DATA Recover 8 uint8 0 31 Number of characters in receiver type field DESI counter N Receiver type 8 N char N 2 ASCI characters describe receiver DF228 ashtech Firmware version Number of characters in firmware version DF229 8 uint8 0 31
134. ide the following signals 2 highest availability 4 1W LIP with Z tracking cannot always be tracked because of the Y code 10 2W L2P with Z tracking cannot always be tracked because of the Y code 15 2S L2C M currently not available The table below shows the status of the observables in terms of Satellite and Signal masks It is seen that the number of Sats is 7 and the number of different signals is up to 4 It is clear that such a status table gives a full vision of all the available signals But generating a complete table can lead to a huge bit consumption On the other hand in most cases the tracking table is sparsely filled and so can effectively be presented by the Capability mask i e by 2 independent masks e Signal mask marked red e Satellite mask marked blue So the potential number of Sat data blocks in this example is 28 4 7 Sats 1112131415 6 1718911011112113 14 15 32 64 Signal mask Signals 1 ashtech CO NY BD TY BY N gt gt gt gt gt N AB WN Satellite mask At the same time not all 4 signals are tracked for every satellite It is seen that actually there are only
135. if some application is talking to GNSS receiver via single physical port e g port A but wants to get more than one fully independent data streams E g some receiver data can be requested to port A some other receiver data or the same data with other parameters can be requested to port Z Both streams will be output via the same physical port A but the data stream corresponding virtual port Z will be additionally packed inside ATM DAT EXT with source ID 25 port Z This packing does not obligatory mean that each message is packed separately on contrary the stream can be cut off quite arbitrarily The only application s w need is supporting parsing ATM DAT EXT transport to split both streams Any s w which supports decoding RTCM 3 transport can easily implement ATM DAT EXT parsing ashtech 3 7 6 ATOM DAT Message INTernal receiver data 3 7 7 DAT Message Universal GNSS raw data frames This message contains raw frames decoded from each tracked GNSS signal with data not pilots The message is universal and applicable to each currently known GNSS signal Given message can be considered as a generic substitute of particular messages DAT GPS GLO SBA GAL Output Logic on change Message Binary size depends on GNSS and signal type How to request PASHS ATM DAT lt Port Name gt ON amp FRM Permissible intervals x sec N A See also N A Table 3 7 7 a
136. ifts assumed the same Total 128 Note e Baseline components are expressed according to the value of Baseline coordinate frame Baseline refers to the vector between L1 antenna phase centers Ifthe baseline flag is set to invalid then the complete block must be considered as invalid and all the fields can take arbitrary values e An invalid baseline estimate does not imply an invalid position in sub block COO e g standalone position for which baseline is not defined where base is coordinates of reference receiver static moving physical or virtual Being expressed in XYZ baseline does not depend on primary GNSS system i e primary datum reported To convert X YZ baseline into any rectilinear ENU system proper default ellipsoid model corresponding to Primary GNSS system is used e Arrow option refers to using or not using a priori knowledge that given baseline has known fixed length If fixed length is not known yet e g Arrow calibration stage then given indicator reports 0 Valid COO and BLN blocks being tagged to the same PVT solution ID source ID and antenna ID are related to each other by the simplest formulae position base baseline Common clock drift indicator can be valuable for so called internal heading configuration or when base and rover boards fed by external occilator ashtech 3 4 8 ATOM PVT Message Sub Block Miscellaneous message This sub block contains various supplementa
137. igation data iia En ans PASHR SBD ashtech 4 GAL GAL raw navigation data aid Universal GNSS raw data Raw navigation data from all 2 ERM frames tracked GNSS Satellites Signals Na Original binary data travelling Data travelling inside receiver via 10 INT inside receiver internal pipes N A Original binary stream Data entering receiver via 11 EXT entering receiver physical virtual port s and sockets N A It must be noted that message FRM is generic substitute of legacy messages GPS GLO SBA GAL Only given generic message will be supported in future by adding support of new GNSS and their signals e g QZSS 3 7 1 ATOM DAT Message GPS Raw Sub Frame 3 7 2 ATOM DAT Message GLONASS Raw String 3 7 3 DAT Message SBAS Sub Frame This message contains an SBAS raw subframe A raw SBAS subframe is 250 bits in total For detailed information about the structure of SBAS raw subframes please refer to the WAAS ICD If parity check failed then corresponding sub frame is not output Output Logic on change Message Binary size 49 bytes 392 bits How to request PASHS ATM DAT lt Port Name gt ON amp SBA Permissible intervals x sec N A See also PASHR SBD Table 3 7 3 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code ash
138. ill insert full extension information to reduce whole time tag ambiguity down to a week number If the time tag is a fractional second then the ATOM generator will insert a fine time tag extension thus allowing data to be generated at up to 200 Hz e leap second occurs the primary time tag is set to 3600 The supported PVT sub blocks are presented in Table 3 4 e Table 3 4 e Supported PVT sub blocks shtech PVT sub ASCII Sub block name Block size Data block nen block type identifier bytes ID subID Counterpart GENERAL PURPOSE BLOCKS 0 Reserved 0000 22 PASHR POS 1 Position 26 0001 Position flags differential age base ID etc GPGGA 2 ERR Accuracy 10 0010 Accuracy lat lon alt errors covariance GPGST PASHR POS 3 VEL Velocity 12 0011 Velocity estimates and its attributes GPVTG 4 CLK Clock 10 0100 Receiver clock estimates and its attributes PASHR PBN 5 LCY Latency 3 0101 Position latency PASHR LTN Heading pitch and roll estimates and its PASHR ATT 6 HPR Attitude 11 0110 attributes GPHDT 7 BLN Baseline 16 0111 3D baseline components and its attributes PASHR VEC GPRMC 8 MIS Miscellaneous 23 1000 Position supplementary data GPGGA GPZDA 9 ROT 13 m Attitude supplementary data N A Parameters Extended 10 BSD Baseline 19 1010 Baseline supplementary data N A parameters 11 Reserved 1011 12 Reserved 1100 Pseudo range
139. imate of the position increment on some interval divided by this interval In this case the true position derivative is tagged to the center of this interval shtech Incase of instant velocity the smoothing interval is that of the corresponding Doppler velocity filter In case of mean velocity the smoothing interval is the exact interval of integrated Doppler In this case the smoothing interval is equal to the upper bound value corresponding to the selected Smoothing interval identifier For example with Smoothing interval identifier 10 the smoothing interval is 3 seconds ashtech 3 4 4 PVT Message Sub Block Clock message This sub block contains receiver clock offset parameters Output Logic on time Sub block Binary size 10 bytes 80 bits How to request PASHS ATM PVT lt Port Name gt ON x amp CLK Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also PASHR PBN Table 3 4 4 a Sub Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Set to 10 Block ID 4 uint4 8 0 15 Set to 4 1 clock steering is applied 12 l 0 clock steering is not applied External clock 1 13 0 1 0 internal clock is used Receiver clock offset 30 i
140. ime shift 6 uint6 100 18 0 63 63 if not defined or invalid See DF054 Magnetic variation 16 int16 106 degree defined or invalid Local zone time offset 11 uintl1 122 l min 0 1439 Value gt 1439 if not defined or invalid 0 almanac used 1 broadcast ephemeris used Type of used ephemeris 3 bit3 133 0 15 2 reserved 7 unknown Firmware version 32 char 4 136 Reserved Reserved 16 bit16 168 0 Set to 0 0 Total 184 Notes 3 4 9 Normally the position reported by the receiver refers to the so called default datum which is generally different depending on the primary GNSS used The default datum can additionally be clarified e g by specifying the ITRF epoch year when GPS is primary Default datum clarification field It must be noted that field DF028 is not still mandatory in RTCM document It is now reserved to output ITRF epoch year That is why user is recommended to ignore its content If field datum is set to custom then extra ATM PVT CDC Custom Datum Clarification block can be generated to clarify what this custom datum is and what its parameters are The receiver can also additionally report position tagged to some local datum See ATM PVT LDP Local Datum Position block for details For Geoid height local zone time offset magnetic variation please refer to NMEA 4 0 definitions The number of GNSS time cycles refers to GPS Week number 0 4095 0 starts midnight January5 January
141. indicate the health of the signal components E 16 uint16 77 27 Eccentricity Toa 8 uint8 93 a Reference time of almanac Ai 16 int16 101 2 19 Inclination at reference time relative to 10 0 3 semi circles OMEGADOT 16 int16 117 27 Rate of right Asc semi circles per sec ROOT A 24 uint24 133 age Square root of semi major axis meters OMEGAO 24 int24 157 9 Longitude of ascending node semicircles Q 24 int24 181 ze Argument of Perigee semi circles MO 24 int24 205 223 anomaly at reference time semi circle 11 intll 229 27 Clock correction sec Afl 11 int11 240 078 Clock correction sec sec Wna 8 uint8 251 1 0 255 Almanac week number ashtech Reserved 5 bit5 259 Set to 00000 END TRANSPORT CRC 24 uint24 264 24 bit Cyclic Redundancy Check Total 288 Note The value of Ai generated from field io Inclination Angle at Reference Time from GPS Ephemeris data is scaled by 0 1 3 6 12 Message Beidou Almanac This message contains Beidou almanac data for a particular satellite For detailed information about Beidou almanac please refer to the Beidou ICD IOpen Service Signal B1I Version 1 0 December 2012 document Output Logic on time on change on new Message Binary size 38 bytes 304 bits How to request PASHS ATM NAV Port Name ON x amp ALM Permissible intervals x sec 1 2 3 etc each integer second but less
142. ine message Output Logic on time Sub block Binary size 16 bytes 128 bits How to request PASHS ATM PVT lt Port Name gt ON x amp BLN Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also PASHR VEC Table 3 4 7 a Sub Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Set to 16 Block ID 4 uint4 8 0 15 Set to7 0 XYZ 1 rectilinear ENU centered on Baseline coordinate frame 3 12 0 7 2 rectilinear centered on base 3 7 reserved static base moving base reserved unknown Base motion assumption 2 uint2 15 0 3 exact base coordinate approximate base coordinates reserved unknown Base accuracy 1 2 uint2 17 0 3 assumption invalid baseline code differential RTK float RTK fixed Baseline flag 2 uint2 19 0 3 mu Ee ashtech 0 Arrow option is not applied 2 1 Arrow option is applied Baseline Ist component 35 int35 22 0 0001 m 1717986 9183 m ee en Baseline 2nd component 35 int35 57 0 0001 m 1717986 9183 m Ditto Baseline 3rd component 35 int35 92 0 0001 m 1717986 9183 m Ditto 0 base and rover clocks Common clock drift assumed different mode 2 1 base and rover clock dr
143. information message 63 3 4 15 ATOM PVT Message Sub Block Position expressed in local eee eee 67 3 4 14 ATOM Message Sub Block Custom datum clarification anna 69 3 4 15 PVT Message Sub Block Position expressed in local cartographic 70 3 5 LX ERE BAN nen ee Nee 72 3 5 2 ATOM ATR Message Antenna Attributes P ae au ea 74 3 5 3 ATOM ATR Message Receiver attributes a see 76 3 5 4 ATR ee ne i EV N A E EE E E Er EAE A EEES SEE TIE ESEESE E 77 3 5 5 ATR Message Antenna offset parameters ico eoe ei J9 3 5 6 ATR Message Site occupation information ann ss PAR tow M 80 3 5 7 ATOM ATR Messasey External Sensors aaa ua aan 82 3 5 8 ATR Messase Meteo Data una ni een 82 3 5 9 ATR Message External Sensors Data Additional 83 32 10 ATOM ATR Message Receiver Installed ODEIIODI nee 83 3 5 11 ATOM ATR Message Receiver Configuration ansehe 83 3 5 12 Messapey GLONASS Eode Phase Das isn ee 83 3 6 Message ee 86 3 6 1 ATOM NAV GPS ee kenne 88 3 6 2 ATOM NAV Messages GLONASS Epic Witt ee aeg 91 3 6
144. inuity indicator of the received L1 carrier phase to prevent the decimated data from being restored incorrectly The decimation DEC option can be applied to static and moving receivers equally However with moving receivers performance degradation is foreseeable higher percentage of missing data on rover side This is because moving receivers are usually more affected by cycle slips and constellation changes than static open sky receivers In combination with possible short term data link outages this can lead to potentially more unavailable epochs on rover side It must be noted that pseudo range and carrier phase data are not the only data that can be decimated There is one extra observable in ATOM which consists of the data identifiers represented by the Satellite Signal and Cell masks see Appendix E In static open sky conditions this identification information does not usually change very quickly This gives a convenient possibility to freeze most of this information i e decimate headers Although a simple idea it is not however trivial to implement because irregular constellation changes as well as short term data link blockage have to be taken into account The careful implementation of the header freezing process in ATOM avoids degrading performance against a static open sky reference receiver Since header data can be considered as an observable along with pseudo range and carrier phase then it was decided that the DE
145. ion ATOM EVT e Receiver alarms ATOM ALR It should be noted that ATOM messages described here are not all necessarily supported by all Ashtech receivers and in all firmware versions Corresponding warning is provided in Product Manuals see Appendix J as an example Some of ATOM messages can be supported outside a GNSS receiver in different service procedures and or PC tools Also the reader should be aware that some indicators inside some ATOM messages can be set as follows Adaptively depending on the current receiver status or Toa fixed value depending on user settings or some hard coded value depending on particular hardware firmware combinations The messages are described independently of each other to allow the reader to concentrate efficiently only on a group of interest That is why redundant information is introduced in each description some general comments being repeated for a number of particular messages fields Before starting with a particular message the reader should first be introduced to the generalized organization of the ATOM group that the given message belongs to When describing a message some short information is provided on how it can be requested what the basic principles are to output this message and what additional cross information can be interesting regarding the message content and request The mechanism used to generate ATOM messages is not part of the ATOM standard but is usually independent of
146. ipment must assume such a possibility A Sat which is visible but not tracked can report single ghost because it is not tracked yet signal in signal mask This is usually signal At the same time such a Sat can report no signals so ATOM PVT SVS parser take into account that while Satellite data are present for it Signal data are absent Table 3 4 12 c Satellite data Data item Bits Data type Offset Scale Range Comments DF Number SATELLITE DATA 0 90 means true positive elevation 91 means true elevation 1 degree 7 92 means true elevation 2 degrees Elevation Nsat times uint7 Nsat 1 degree etc 126 means true elevation less equal to 36 degrees 127 means invalid elevation Azimuth ae uint8 Nsat 2 0 358 gt 358 means invalid azimuth 0 Sat is not tracked AF008 4 1 no corrections applied Sat correcting status uint4 Nsat 0 15 2 14 corrections applied Nsat times 15 not known status See Appendix G 0 Sat is not tracked u AF007 1 3 Sat is used in position 5 4 14 Reserved Sat usage status Nsat times uint5 Nsat 0 31 i5 not known status 16 31 Sat is not used in position See Appendix G Total 24 Nsat Notes Nsat is the number of visible satellites for a given GNSS It is equal to the number of 1 s in the Satellite mask field Each particular field uses internal looping e g the Elevation field includes sequentiall
147. is no projection parameters for given COO position at given epoch then block LMP is not generated or generated with indication all or some of fields as invalid For example in some cases some projection parameters are valid only for differential e g RTK position in such cases when receiver transits to standalone or SBAS differential position e g data link lost block LMP can be not generated Output Logic on time Sub block Binary size depend on message content How to request PASHS ATM PVT lt Port Name gt ON x amp COO Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also GPGMP Table 3 4 15 a Sub Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Depends on block content Block ID 4 uint4 8 0 15 Set to 15 Sub Block Id 8 uint8 12 0 255 Set to 3 Northing 41 int41 20 Simm ber c 10999 02 ot denned or invalid Easting 109951162 7776 m if not defined or 41 int41 61 lmm 1099511627775 invalid ashtech m 29 int29 108 din esam invalid Reserved 5 bit5 131 Set to 0 0 XC 170 if source Projection Type 6 uint6 136 Undefined otherwise See DF170 Reserved 18 bit18 142 Set to 0 0 Geoidal separation 21 int21 160 Imm
148. it interval is 1 the Ephemeris data are effective for more than 2 hours END TRANSPORT CRC 24 uint24 552 24 bit Cyclic Redundancy Check CRC Total 576 Notes 3 6 6 Message Beidou Ephemeris This message contains Beidou ephemeris data for a given Beidou satellite For detailed information about Beidou ephemeris data please refer to the Beidou ICD IOpen Service Signal Version 1 0 December 2012 document Output Logic on time on change on new Message Binary size 76 bytes 608 bits How to request PASHS ATM NAV lt Port Name ON x amp EPH Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also Table 3 6 6 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT ashtech Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 anti 14 m length in bytes Set to 70 for this MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 NAV message type 9 uint9 55 0 511 2 2
149. kind of showstopper The problem is that some signal L1 pseudo range is selected as primary observable while all the other secondary signals e g L2 pseudo range L1 amp L2 carrier phase are generated as the difference against this primary signal With the multiple signals we now get from each GNSS it seems that such a primary secondary concept is not convenient It has at least the following disadvantages e Invalid L1 pseudo range for whatever reason automatically leads to inability to present all the other data There is no possibility to send L2 data without sending L1 data Earlier this was not so important but with the current and future availability of L2C and L5 such L1 centered scheme can be ineffective L5 only receivers can be manufactured in future e There is no possibility to send carrier phase data without sending pseudo range Carrier phase data have some interest primarily for precise applications while well smoothed pseudo range data are usually not needed with the same update rate as the carrier phase Of course there already exists some actions to mitigate the negative effect of the L1 pseudo range centered scheme However all of them are not so effective compared to the rough fine range concept used in ATOM The idea behind the rough fine range concept used in is very simple each GNSS observable contains a regular term and a specific term e Under regular term we
150. l seconds since the beginning of the DF397 GALILEO Orbit Galileo week Note a bit pattern equivalent 563 Is to fffffh in this field indicates the given Galileo time of week is invalid respectively not set Reserved 1 bit 1 583 Set to 0 Elb Signal Health 2 bit 2 584 Unitless Status Elb Data Validity 1 bit 1 586 Unitless Status E5b Signal Health 2 bit 2 587 Unitless Status E5b Data Validity 1 bit 1 589 Unitless Status The Source of decoded 2 uint2 0 3 0 Elb ephemeris 1 E5b 20 2 Elb amp E5b 3 unknown END TRANSPORT CRC 24 uint24 592 24 bit Cyclic Redundancy Check Total 616 Note 1 Effective range is the maximum range attainable with the indicated bit allocation and scale factor Note 2 The message is extended copy of RTCM MT 1046 draft as appears on February 2012 ashtech 3 65 NAV Message 0755 Ephemeris This message contains QZSS ephemeris data for a given QZSS satellite For detailed information about QZSS ephemeris data please refer to the IS QZSS_13 E document The content of QZSS ephemeris message is a copy of corresponding GPS ephemeris message the same size with some fields set to fixed values or with slightly another meaning Output Logic on time on change on new Message Binary size 72 bytes 576 bits How to request PASHS ATM NAV lt Port Name gt ON x amp EPH Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR SNV RTCM 3 Messag
151. ll restored range m dFullPhase Full restored phase m dCalcRange Calculated using ephemerids range the same as used in RTCM3 1001 1003 1009 1011 range restoring m eRangePresent 1 Compact 2 Compact Rough 3 Compact Rough Nms dLyambda wave length m about 0 19 for L1 ePhasePresent phase presentation is always full modulo 4096 cycles if eRangePresent 3 dReference Nms dRoughRange F64 LIGHT MSEC moving from ms gt meter scale lse if eRangePresent 2 dReference dCalcRange fAmbiguity F64 LIGHT MSEC 1 fModulo dRoughRange dReference RestoreFullMeas dReference fAmbiguity fModulo lse if eRangePresent 1 dReference dCalcRange fAmbiguity 655 36 shtech fModulo dFineRange dFullRange RestoreFullMeas dReference fAmbiguity fModulo fAmbiguity 4096 dLyambda fModulo dFinePhase dFullPhase RestoreFullMeas dReference fAmbiguity fModulo float64 RestoreFullMeas float64 dReference float64 fAmbiguity float64 fModulo float64 dClosest ROUND dReference fAmbiguity fAmbiguity find nearest on ambiguity scale float64 dFull dClosest fModulo full range which can have error fAmbiguity float64 dDelta dFull
152. lock ATM PVT CDC is added Reference documents dates updated 1 14 June 30 2010 ashtech PVT solution ID clarified in section 3 4 Correction usage status clarified in section 3 4 10 Time interval usage clarified for DAT and STA messages in sections 3 4 Notes about clock steering effect on position added to 3 4 4 and 3 8 5 message mention is added to Appendix G 2 The response to PASHQ PAR ATM is updated Added note in 2 5 about possible GLONASS observation corrections to golden Ashtech receiver Reference documents dates updated 1 15 July 31 2010 Message STA BLA modified earlier reserved fields are now populated Message STA DDS introduced Message STA DPS introduced Message STA RSA introduced Message STA RSP introduced Message STA EGB introduced Few clarification sentences added to ATM PVT and ATM DAT description 1 16 Aug 31 2010 Description of field AF006 Appendix G 1 clarified New ATM NAV message for Galileo Ephemeris introduced but not finalized New ATM DAT message for Galileo Navigation data stream introduced but not finalized GALILEO indication bits are added to PVT and RNX messages GALILEO as primary GNSS system is not yet defined Few clarifications are given for STA messages Sept 30 2010 Message ATM STA DDS is modified Message ATM STA DLS is added The logic to output ATM STA messages 15 clarified Bits bytes boundaries and offsets are finalized in ATM STA mes
153. lock of data at the end of ATOM message Availability of such extra data shall be considered as a normal occasion and shall not result in raising warning flag e Encoding software shall NOT use this possibility for undocumented proprietary data transmission No any extra information shall be added to the end of MSM message by encoding software unless this would comply with the next releases of ATOM Manual If the original known 4095 message does not contain an integer number of bytes then the needed number of zero bits 0 to 7 is added at the end of the message to make the whole number of bytes an integer The high level presentation form of message 4095 is the following Data item Number Range Comments of Bits Message number 12 1001 4095 111111111111 4095 reserved for Ashtech ashtech Message group sub number 4 0 15 Message group clarifier e g 0011 3 reserved for PVT Message version number 3 0 7 ATOM message version Set to or 2 for this release Message body lt 8165 2 2 Wrapping basic ATOM 2 3 Short ATOM overview To date ATOM ver 1 2 supports the following primary groups of GNSS data Group type Group ID Message clarifier Standardized counterparts Group configuration Receiver alarms 4095 0 or ATOM ALR 0000 N A Group of independent messages or single composite message Supplementary data 4095 1 or ATOM SUP 0001 N A Gr
154. lt Port Name gt ON x amp COO Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also PASHR POS GPGGA Table 3 4 1 Sub Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Set to 26 Block ID 4 uint4 8 0 15 Settol 0 invalid fix 1 standalone 2 diff corrected including SBAS corrected 3 GPS PPS mode Position type GGA 4 RTK fixed presentation 2 a 5 RTK float 6 dead reckoning 7 entered position 8 simulator mode 9 14 reserved 15 not defined Bitl GPS is used in position GNSS usage mask 8 bit8 16 0 255 Bit2 GLONASS is used in position Bit3 GALILEO is used in position ashtech Bit4 SBAS ranging is used in position 5 QZSS is used in position Bit6 Beidou is used in position Bit7 8 Reserved for other GNSS 0 3D GNSS position 1 2D position with entered altitude Position mode 3 uint3 24 0 7 2 2D position with frozen altitude 3 6 reserved 7 not defined 0 not smoothed 1 averaged static position Position smoothing 3 uint3 27 0 7 2 smoothed kinematic position 3 6 reserved 7 not defined Reserved 4 bit4 30 0 15 Set to 0 0 PDOP 10 uintl0 34 0 1 0 102 2 Corresponds to satellites
155. ly following SNRs for all available signals e Good quality means that no warning flags are set for a given signal Medium quality and questionable quality mean that some set of warnings is associated with the signal See detailed warnings description in ATM RNX message SNR 0 and or smooth count 0 does not necessarily mean that the signal is not tracked and or not used in internal receiver position Medium questionable quality does not necessarily mean that these data are not used in internal receiver position ashtech 3 413 ATOM PVT Message Sub Block Position expressed in local datum This sub block contains the same position as in COO block but expressed in a local datum Local datum description name is also provided There is no need to request this block specially each time when COO block is generated and transformation parameters corresponding to COO positions are available block LDP is generated If there is no transformation parameters for given COO position at given epoch then block LDP is not generated For example in some cases some transformation parameters are valid only for differential e g RTK position in such cases when receiver transits to standalone or SBAS differential position e g data link lost block LDP can be not generated Output Logic on time Sub block Binary size depend on message content How to request PASHS ATM PVT lt Port Name gt ON x amp COO Permissible intervals x sec 0 05 0 1 0 2 0 5
156. mean approximate range to a given satellite from a given position at a given receiver time This regular term is the same for any type of observable corresponding to a given satellite Moreover it does not contain site specific information because it can be estimated restored easily providing ephemeris and reference position are available e Under specific term we mean thin components including site specific information such as local ionosphere troposphere conditions receiver biases and multipath This information cannot be restored That is why it is often possible to generate only the specific term and not regular term as the latter can be restored on decoding side To apply effectively this concept the reference receiver should apply the following obvious principles The carrier phase observable must be matched to the corresponding pseudo range by proper adjustment of the integer number of cycles shtech All receiver observables must be receiver clock steered to guarantee minimum possible receiver clock error These 2 principles are general for each standardized RTCM 3 observable can generate the regular term as the so called rough range which has not exactly a physical meaning but is rather some technological value that will be used on decoding side to restore the complete observable There can be different algorithms to generate rough range based on e Some particul
157. n be tagged to another GNSS time Figure 3 8 1 Time tag organization Depends on extension type Table 3 8 1 b Time tag presentation Primary Time Tag Time Tag Time Tag extension type extension Full BF Fine Time Tag Time Tag ashtech Data item Bits Data type Offset Scale Range Comments DF Number Primary time tag 12 uintl2 0 1 second 0 3599 END invalid time 1 fine time tag extension follows a pH 2 iR 0 full time tag extension follows Tinie catension 8 13 m tag extension see the tables Total 21 Table 3 8 1 c FULL Time tag presentation Data item Bits Data type Offset Scale Range Comments DF Number Hour 5 uint5 0 1 hour 0 23 GNSS hour within GNSS day ashtech Set to GPS day 0 6 within GPS week 0 is Sunday 1 is Monday etc Set to GLONASS day 0 6 within GLONASS week 0 is Sunday 1 is Monday Day 3 uint3 5 1 day 0 6 etc Set to BDS day 0 6 within BDS week 0 is Sunday 1 is Monday etc In each case 7 refers to unknown day Total 8 Table 3 8 1 d FINE Time tag presentation Data item Bits Data type Offset Scale Range Comments DF Number Fractional second 8 uint8 0 5 ms 0 995 GNSS time modulo 1 sec Total 8 Notes time tag always refers to the time scale of the
158. n the I NAV frames is 36 satellites 3 planes of 12 satellites each Aa 13 int13 70 29 Difference with respect to the square root of the nominal semi major axis meters e 11 uintl 1 83 2 Eccentricity dimensionless Ai 11 intll 94 2 4 Inclination at reference time relative to io 56 semi circles per sec 16 int16 105 278 Right ascension semi circles 11 int11 121 29 Rate Right ascension semi circles per sec Q 16 int16 132 ds Argument of Perigee semi circles Mo 16 int16 148 2 15 anomaly at reference time semi circle n 16 int16 164 2 19 Satellite clock correction bias truncated sec 13 int13 180 258 Satellite clock correction linear truncated sec sec IODa 4 uint4 193 toa 10 uint10 197 600 Almanac reference time sec Wna 2 uint2 207 1 Almanac reference week number week ashtech Reserved 8 Bit 8 209 E1 B Signal Health bit 2 Unitless 2 217 Status Reserved bit 1 Because in GAL ALM there is no data 1 219 REN validity bits E5b Signal Health 2 bit 2 220 Unitless Status Reserved bit 1 Because in GAL ALM there is no data 1 222 dip validity bits Source of decoded uint2 0 from E1 B 1 from E5b 2 used 2 223 ephemeris booth 3 unknown Reserved 7 bit 7 225 END TRANSPORT CRC 24 uint24 232 24 bit Cyclic Redundancy Check CRC Total 256 3 6 11 Message QZS
159. ng carrier processing or to sew respective carrier measurements ashtech Reference position refers to the default datum associated with the GNSS indicated as primary in the Message header see Table 3 8 1a Depending on the position presentation flag in the Message header see Table 3 8 1a the reference position can be generated in one of the following 4 different forms 3 8 5 Reference position e No reference position Compact reference position see table 3 8 5a Compact reference position clarification data see table 3 8 5b e Compact reference position clarification data velocity amp clock see table 3 8 5c Table 3 8 5 a Compact reference position Data item Bits Data type Offset Scale Range Comments DF Number REFERENCE POSITION Motion flag 1 bit 0 0 1 17 27 1 moving 0 mm accuracy 1 fixed cm 2 float dm accuracy 3 DGNSS sub meter accuracy 4 Standalone a few meters Position quality flag 3 uint3 1 0 7 5 Rough hundreds meter accuracy 6 Approximate km level accuracy 7 unknown Reserved 7 bit7 4 0 127 Set to 0000000 0 Antenna reference point 1 L1 phase center Position tagging 3 uint3 11 0 7 2 5 reserved 6 Ground mark 7 Unknown X coordinate 38 int38 14 89238955 aa E ento 055 472 m invalid ashtech
160. nge counter has not changed meanwhile ver 1 defines Sat mask size 40 bits and Signal mask size 24 bits The meaning of first 40 bits in Sat mask v 2 and Sat mask v 1 is the same The meaning of first 24 bits in Signal mask v 2 and Signal mask v 1 is the same Decoding equipment must analyze ATOM RNX version number and process all the other fields accordingly ashtech 3 8 3 Satellite data Satellite data have 3 optional blocks that can be inserted in the message depending on configuration bits in the Observable mask see Table 3 8 2a These blocks contain information common to each signal from the same satellite In each of these 3 blocks the field s having the same meaning for each of the satellites from a given GNSS are internally repeated Nsat times in order to output the value s of this or these fields for each of the satellites The value of Nsat is known after decoding the Capability mask see Table 3 8 2b Table 3 8 3 a Satellite data Data item Bits Data type Offset Scale Range Comments DF Number STELLITE DATA Integer number of ms in 8 x dint BN oe 0 255 Inserted if Nms follows DF397 Satellite ranges Nsat times Set to 255 if not known See DF398 Satellite rough range 10x uintl0 N 1 1024 ms 0 1023 Inserted if full pseudo range modulo 1 ms Nsat times 1024 ms follows Extended Satellite 32x bit32 N Inserted if full supplementary data supplementary d
161. nosphere and time shift parameters For detailed information about these parameters please refer to the GALILEO OS SIS ICD September 2010 document Output Logic on time on change on new Message Binary size 34 bytes 272 bits How to request PASHS ATM NAV Port Name ON x amp GIT Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR ION Table 3 6 15 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes Set to 28 for this message shtech MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 9 ain Species which NAV messge follows Fo MESSAGE DATA a0 T uintl1 64 22 level 1 st order a IE en 2 2 SF1 1 bit 100 Ionospheric disturbance Flag for region 1 SF2 1 bit 101 Ionospheric disturbance Flag for region 2 SF3 1 bit 102 Ionospheric disturbance Flag for region 3
162. nt30 14 0 001 m 1 536870 912 if not defined or invalid Receiver clock drift 22 int22 44 0 001 m s 1 5 Bp 2097 152 if not defined or invalid TDOP 10 uint10 66 0 1 0 102 2 102 3 if not defined or invalid Reserved 4 bit4 76 0 15 Set to 0000 Total 80 Notes A receiver can apply or not apply the so called clock steering procedure However the receiver clock offset and drift reported in this message always refer to the original internal receiver clock which is typically within 300 km or so A receiver can be clocked from an internal or external usually very stable oscillator The corresponding bit is therefore provided shtech Reported receiver clock offset and drifts as well as TDOP value refers against primary GNSS system specified in PVT message header e t must be noted that clock steering procedure affects reported position block COO for very high dynamic receiver In this case user who desires to return to original receiver status not steered will have to correct reported position COO using the knowledge of reported receiver velocity block VEL and internal clock offset given block ashtech 3 4 5 ATOM PVT Message Sub Block Latency message This sub block contains latency of given ATM PVT message Output Logic on time Sub block Binary size 3 bytes 24 bits How to request PASHS ATM PVT lt Port Name gt ON x amp LCY Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120
163. ntX X bit unsigned integer 0 to 1 uint8 8 bit unsigned integer intX X bit 2 s complement integer gp 1 int8 8 bit 278 complement integer 111814 14 bit sign magnitude integer intSX X bit sign magnitude integer 2 1 see notes below char X 8 bit character set with total Character set with length in X chars variable length utf8 X Unicode UTF08 Code Unit Unicode set with variable length Note The intS data type refers to a sign magnitude value The sign magnitude representation records the number s sign and magnitude MSB is 0 for positive numbers and 1 for negative numbers The rest of the bits are the number s magnitude For example for 8 bit words the representations of numbers 7 and 7 in a binary form are 10000111 and 00000111 respectively Negative zero is not used The convention used for the Most and Least Significant Bits MSB and LSB for signed and unsigned data is presented in the diagram below Data follow this direction Bit location in N bit integer MSB LSB ATOM uses a number of bit masks indicated as field bitX referring to GNSS set being transmitted GNSS mask Satellites being present Satellite mask Signals available Signal mask and many others In all these masks the first bit is the bit with goes first in binary stream and the last bit is the bit which goes last in binary stream shtech To insure quick reference to ATOM data fields numerical equivalents
164. ntennae MRMS 10 uint10 64 0 001 m 0 1 022 1 023 means not defined or invalid BRMS 10 uintl1O 74 0 001 0 1 022 1 023 means not defined or invalid Reserved 4 uint4 84 0 15 See Appendix G AF024 Total 88 shtech Note Forthe description of fields MRMS and BRMS see ATT message definition The BRMS field is reported invalid if the lengths of baselines are not known a priori e When antenna setup 1 2 3 then reported angles refer to platform where antennae installed on attitude When antenna setup 0 then reported heading refers to baseline azimuth reported pitch refers to baseline elevation roll is reported as invalid e When single baseline 2 antennae is applied for attitude estimation either pitch or roll or both is not available When 2 and more baselines 3 antennae are applied for attitude estimation all angles can be generally available But in some singular cases some of 3 angles can be not available even with 3 antennae Incase of single baseline block being transmitted with BLN block under the same PVT header indicates that content is based BLN estimate ashtech This sub block contains baseline estimates These estimates are applicable only to MS differential operation Here MS refers to Measurement Space corrections by contract to Stage Space SS corrections for which SS baseline is not defined at all 3 47 ATOM PVT Message Sub Block Basel
165. o data 1 3 1 1 4 1 B I NAV 1B OS CS SoL 5 El B C 1X 6 El A B C 17 7 Reserved 8 E6 6 9 E6 A 6A 10 E6 B 6B 11 E6 B C 6X 12 E6 A B C 6Z 13 Reserved 14 ESB I 71 15 5 Q 70 16 5 I Q 7X 17 Reserved 18 E5 A B I 81 ashtech Signal ID in Signal Frequency Signal GALILEO Comments Notes Mask DF395 Band signal RINEX code 19 5 80 20 5 I Q 8X 21 Reserved 22 5 51 23 5 Q 5Q 24 5 X 5X 25 32 Reserved QZSS Satellite ID mapping Satellite ID in Satellite Mask DF394 QZSS Satellite PRN 1 193 2 194 10 202 11 64 Reserved 0755 Signal ID mapping signal L1 SAIF is interpreted as SBAS Signal IDin Frequency Signal QZSS signal Comments Notes Signal Mask Band RINEX DF395 code 1 Reserved 2 11 1 3 14 15 12 12 25 16 12 L2C L 2L 16 L2 L2C M L 2X 17 21 Reserved 22 15 1 51 ashtech ashtech Signal IDin Frequency Signal QZSS signal Comments Notes Signal Mask Band RINEX DF395 code 23 15 Q 50 24 15 1 5 24 32 Reserved Beidou Signal ID mapping Signal IDin Frequency Signal QZSS signal Comments Notes Signal Mask Band RINEX DF395 code 1 Reserved 2 Bl I 11 3 B2 Q 1Q 4 13 Reserved 14 B2 I 71
166. ocused on the latter case while staying a general description of the message Observables presented in the ATOM RNX messages are steered for the receiver clock offset At the same time an optional ATOM RNX block provides the original receiver clock offset and clock drift So the decoding equipment can restore original i e not steered observables if needed The particularities that stand behind generating presenting and restoring the ATOM RNX message can be found in Section 5 and Appendixes C D and The understanding of ATM RNX organization can be helped with Ashtech ION GNSS 2012 paper Session D5 Multi Constellation User Receivers The RTCM Multiple Signal Messages A New Step In GNSS Data Standardization A Boriskin D Kozlov G Zyryanov Ashtech Russia The paper deals with standardized RTCM 3 2 Multiple Signal Messages MSM which are simplified copy of ATOM RNX messages The basic principles of ATOM RNX messages originated standardized RTCM 3 2 generic MSM data These are the messages 1071 1077 GPS 1081 1087 GLONASS 1091 1097 GALILEO etc This means that generating and processing Ashtech proprietary ATOM RNX messages and standardized RTCM 3 2 MSM data has very much in common The default ATOM RNX message can be enabled disabled using the following command PASHS ATM RNX lt Port Name gt ON OFF The general organization of the RNX message is presented below shtech
167. onents correspondingly as defined by used coordinate frame reported BLN block The below is correspondence between covariance matrix elements and BSD fields the formulae is the same as for ERR block referring to COO accuracy If Sigma is set to an invalid value then all other fields in this sub block are also invalid and can take arbitrary values Sigma 811 522 533 meter kl l k2 ae k3 all unitless sigma sigma sigma 512 513 523 rl2 all square unitless 1 r232 4 s11 522 s11 533 4 522 533 Reported covariance matrix needs not any additional scaling because reports actual 1sigma baseline accuracy figures E g random variable ratiol errl sqrt s11 should theoretically follow Gaussian 0 1 distribution Additionally the block reports baseline extrapolation if applied interval with resolution 10 ms and Base station ID I good number of reserved bits are created to support more baseline supplementary data in future shtech 3 4 41 ATOM Message Sub Block Pseudo range residuals message shtech 3 4 12 Message Sub Block Satellite information message The content of given block is ATOM PVT version dependent This sub block contains the status of each visible by almanac satellite No SNR elevation and other masks are applied to output satellites status One SVS sub block describes the status of a single GNSS If a receiver tracks
168. or applicability CPB value to GLONASS FDMA observations please see the description of RTCM 3 MT 1230 The content of given message is equally applicable to all raw differential proprietary standardized data generated by Ashtech receiver from legacy MCA MPC and 2 towards modern ATM RNX and RTCM 3 MSM Output Logic on time Message Binary size depends on message content How to request PASHS ATM ATR lt Port Name gt ON x amp CPB Permissible intervals x sec 1 2 3 etc each integer second but less than 999 ashtech See also ATM RNX RTCM 3 MSM RTCM 3 MT 1230 Table 3 5 12 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 Bit6 8 Set to 000000 Message Length 10 uint10 14 Message length in bytes MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 4 is reserved for ATOM ATR message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 ATR message type 9 uint9 55 0 511 Specifies which ATR message follows For this message set to 8 MESSAGE DATA 0 the GLONASS data are not corrected DF421 SETS 1 bitl 64 1 GLONASS data are corrected to Golden Bias indicator RUD r
169. orrection term radians IDOT 14 int14 497 97 Rate of inclination semicircles sec 0 32 int32 511 2 Longitude of ascending node semicircles o 32 int32 543 2 Argument of perigee semicircles reserved 9 bit9 575 END TRANSPORT CRC 24 uint24 584 24 bit Cyclic Redundancy Check CRC Total 608 Notes ashtech This message contains GPS almanac data for a given GPS satellite For detailed information about GPS almanac data please refer to the ICD GPS 200 document 3 67 NAV Message GPS Almanac Output Logic on time on change on new Message Binary size 36 bytes 288 bits How to request PASHS ATM NAV lt Port Name gt ON x amp ALM Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR SAL Table 3 6 7 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to OXD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes Set to 30 for this message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 message type 9 uint9 55 0 5
170. orts Request ID 0 in the header PASHS ATM ANG lt Port Name gt ON OFF lt Per gt This message content is PVT content but it refers to secondary solution Given message reports Request ID 1 in the header ashtech 5 COMPRESSION OPTIONS FOR ATOM RNX OBSERVABLES shtech 6 UTILITIES There are four primary Ashtech PC tools which help viewing processing ATOM messages AshCom PC terminal program to talk to GNSS receivers and view its status DataView AtlView PC tool to process view precollected GNSS data files Whatls console executable to get ascii content and statistic of most of binary GNSS data e Bin2Std console converter of ATOM data to standardized messages files Each tool has own description available separately Ask Ashtech Technical Support for corresponding tools shtech Appendix A PASHR transport decoding sample ushtech Appendix B ATOM message decoding sample Using an example of ATOM NAV GPS ephemeris message this Appendix gives the method to decode an ATOM message from binary to ASCII Full binary message content D3 00 42 FF F5 20 3E 01 3F B2 1D 90 03 03 2A 72 42 00 FF F1 E9 54 2A FC 95 2A 94 14 A6 FO 58 8B 05 69 06 13 E2 Al 0 C9 32 72 42 00 59 29 D9 58 E4 28 22 18 45 19 F5 76 70 BA D7 FF AB 27 F8 02 D8 8221 Parts of the message D3 00 42 Start Transport 3 bytes FF F5 20 01 Message Header 5 bytes B2 1D 90 03 03 2A 72 42
171. ositioning results such as position velocity clock offset and Satellite tracking usage status Additionally it contains the information about position latency and accuracy These data can be converted to or generated from standardized NMEA 3 messages A more detailed view on the ATOM PVT architecture is given in a separate section below Group ATR generates receiver antenna attributes for example receiver name serial number firmware version and or antenna name serial number It is also used to specify the antenna reference point with respect to survey point as well as any user defined message generation Group NAV generates navigation data extracted from GNSS data streams NAV supports the generation of GPS GLONASS SBAS GALILEO QZSS BEIDOU ephemeris and almanac data as well as some other valuable information like broadcast ionosphere parameters Group DAT generates a raw navigation data stream frames decoded from any signal a GNSS receiver tracks Also this group includes messages containing the binary streams entering the receiver through its physical ports e g external differential data stream Group STA provides status information from some receiver firmware modules Particularly it can output the current receiver configuration parameters the differential data link status etc Group EVT generates some information about events inside a receiver It can be the precise time tagging of the external event marker or PPS time tagging Gro
172. oup of independent messages Reserved 4095 2 Reserved for future group Positioning results 4095 3 or ATOM PVT 0011 NMEA 3 GGA GST GSV etc Group of independent messages or single composite configurable message Receiver attributes 4095 4 or ATOM ATR 0100 RTCM 3 1007 1008 1029 1033 Group of independent messages Navigation information 4095 5 or ATOM NAV 0101 RTCM 3 1019 1020 Group of independent messages Data frames 4095 6 or ATOM DAT 0110 N A Group of independent messages GNSS RINEX observables 4095 7 or ATOM RNX 0111 RINEX 3 3 MSM Group of independent messages or single composite configurable message Reserved 4095 8 9 10 11 12 Reserved for future groups Receiver status 4095 13 or ATOM STA 1101 N A Group of independent messages Receiver events 4095 14 or ATOM EVT 1110 N A Group of independent messages Any non RTCM 3 message 4095 15 1111 N A Just transport layer to pack any other message Not described in given Manual The most of existing ATOM groups is available for 3 party users At the same time there are reserved groups and respective messages numbers which are proprietary and not available for end users If third party equipment detects such groups messages it must ignore them Group RNX refers to ATOM observables Depending on the desired application and personal preferences different configurations scenarios may be used A short overview of this group is given below shtech Group PVT delivers p
173. p and loss of lock indicators are not set with transition from 1 to 0 Indicators relating to carrier phase carrier quality cycle slip possible and loss of continuity actually refer to the interval between the current and previously generated ATOM RNX epoch and not to the receiver time tag Cumulative twin of loss of continuity bit is available in the field integer cycle carrier phase data Smoothed Doppler means that is was derived from carrier phase samples through appropriate filtering Not smoothed Doppler refers to Doppler extracted directly from carrier frequency tracking loop NCO Matching table for pseudo range quality E m MPC bit3 MPC bit 4 Good 0 0 0 Satisfactory 1 Admissible 2 0 1 shtech shtech 3 9 ATOM SUP Messages shtech 3 10 ATOM EVT Messages shtech 3 11 ATOM STA Messages 3 12 ATOM ALR Messages ashtech 4 ATOM SERIAL INTERFACE This chapter is organized as follows First we describe the simplest ways to request each group of ATOM messages Second we describe how to request each particular ATOM sub message or sub block from groups SUP PVT ATR NAV DAT STA and EVT Then we show how to customize ATOM observables messages RNX for user specific needs 4 1 Getting started To request the output of any of the ATOM groups on a specified port with its default parameters use the following command P
174. positions but it will be obviously extended e Galileo reserves 36 positions but it cannot be guaranteed QZSS reserves 10 positions 5 by other sources BeiDou reserves 36 positions but it cannot be guaranteed E Signal mask is a bitset indicating which signals from a given GNSS are available from at least one of the multitude of tracked satellites The Signal mask includes 32 bits Each bit is representative of a specific GNSS signal The definition of Signal mask bits for each GNSS is given in Section 3 3 Below is combined compact table for more clear reference Signal mask It must be noted that additionally to RINEX definitions we reserved choices 1 2 and 5 They are very useful in cases when some legacy data are converted into ATOM while the exact type of signal is known In other words 1 stands for any L1 signal which type is not known Rank GPS SBAS GLONASS Galileo QZSS BeiDou RINEX code RINEX code RINEX code RINEX code RINEX code RINEX code 1 1 1 1 1 1 2 1 1 1 1 1 3 10 4 IW 1B 5 6 7 2 2 2 8 2C 2C 6C 9 2P 2P 6A 10 2W 6B 11 6X 12 6Z 13 14 71 71 15 28 7Q 25 70 16 2L 2L 17 2X 2X 18 81 19 8Q 20 ashtech ashtech 21 5 5 5 5 2 51 51 51 51 2 50 50 50 50 24 25 26 27 28 29
175. primary GNSS system used e g UTC Nls where Nls is the number of leap seconds 1 15 as from Jan 1 2009 and 16 as from July 2012 for GPS and UTC 3 hours for GLONASS size of the time tag is always fixed e Inthe most of the cases i e for the most of supported ATM RNX scenarios the message is not generated if correct primary GNSS time is not known For example GPS can be set as primary system but GPS can be not tracked In this case correct primary system time can be not available and other than GPS GNSS data will not be generated e Using the switchable time tag presentation users can cover a full range of GNSS time tags with fine resolution If the time tag is an integer second the ATOM generator will insert full extension information to reduce whole time tag ambiguity down to a week number If the time tag is a fractional second then the ATOM generator will insert a fine time tag extension thus allowing data to be generated at up to 200 Hz e Ifa leap second occurs the primary time tag is set to 3600 if GPS is primary ashtech The GNSS header is described below by sequentially introducing the description of the Observable mask fixed size the optional Capability mask fixed size and the optional Cell mask float size 3 8 GNSS header Table 3 8 2 a Observable mask Data item Bits Data type Offset Scale Range Comments DF Number OBSERVAB
176. rdware target and firmware version ATOM RNX generator can apply any combinations of the above strategies Under no circumstances ATOM RNX generator will adjust one signal to another to make a cloud compact It is a well known task to restore full measurement value using its two samples High precision but ambiguous part Low precision but fully known part If somebody has dealt with RTCM3 1001 1003 1009 1011 messages he she also faced this problem Here one should restore full raw range from raw range modulo I ms with the help of calculated rough range using ephemeris Let us see some examples to understand the physics CalcRange 70 56 ms RangeModulolms 0 52 ms Full Range 70 52 shtech CalcRange 70 97 ms RangeModulolms 0 03 ms Full Range 71 03 CalcRange 70 01 ms RangeModulolms 0 99 ms Full Range 69 99 When we have only ambiguity part we have unlimited number of solutions blue circles Module value A pt Ambiguity m e e y e o o To choose only one the best we add some reference low precision value The best solution is that which is closest to reference Reference value ok Adequate reference range is needed to restore original receiver observables In this reference depends type of range presentation Range presentation 2 Rough range R follows and Nms is available e
177. rence station ID DF003 ATR message type 9 9 55 0 511 Specifies which ATR message follows For this message set to 5 MESSAGE DATA Modified Julian Day number MJD is the DF051 Modified Julian Day 16 uintl6 continuous count of day numbers since MJD Number November 17 1858 midnight Seconds of Day UTC are the seconds of DF052 the day counted from midnight Greenwich time GPS seconds of week have to be Seconds of Day UTC 17 uint17 adjusted for the appropriate number of leap seconds The value of 86 400 is reserved for the case when a leap second has been issued This represents the number of fully formed DF138 Unicode characters in the message text It is Number of characters to 7 uint7 not necessarily the number of bytes that are follow needed to represent the characters as UTF 8 Number of UTF 8 code The length of message is limited by this DF139 8 uint8 units field er EEE gah utf8 N Code units of a Unicode 8 bit string 5 24 uint24 24 bit Cyclic Redundancy Check Total ashtech 3 5 5 ATR Message Antenna offset parameters This message contains some antenna offset parameters expressed with respect to the survey point Output Logic on time Message Binary size 22 bytes 176 bits How to request PASHS ATM ATR lt Port Name gt ON x amp AOP Permissible intervals x sec 1 2 3 etc each integer second but less than 9
178. ris data reference time within the To 13 uint13 80 16 day expressed in the SBAS time scale seconds Accuracy 4 uint4 93 Accuracy Rx 30 int30 97 0 08 Satellite ECEF X coordinates meters Ry 30 int30 127 0 08 Satellite ECEF Y coordinates meters Rz 25 int25 157 0 4 Satellite ECEF Z coordinates meters Vx 17 int17 182 0 000625 Satellite ECEF velocity X coordinates m s Vy 17 int17 199 0 000625 Satellite ECEF velocity Y coordinates m s Vz 18 intl8 216 0 004 2 ECEF velocity Z coordinates ashtech Ax 10 int10 234 0 0000125 Satellite ECEF acceleration X m s Ay 10 int10 244 0 0000125 Satellite ECEF acceleration Y m s Az 10 int10 254 0 0000625 Satellite ECEF acceleration Z m s on p mmo gt gt Ne Reserved 4 bit4 284 Set to 0000 END TRANSPORT CRC 24 uint24 288 24 bit Cyclic Redundancy Check CRC Total 312 3 6 4 NAV Message Galileo Ephemeris This message contains Galileo I NAV ephemeris data for a given Galileo satellite These data are extracted from Galileo Elb or E5b signal For detailed information about Galileo ephemeris data please refer to the GALILEO OS SIS ICD The content of given message is the extended copy of RTCM 3 MT 1046 draft Output Logic on time on change on new Message Binary size 77 bytes 616 bits How to request PASHS ATM NAV lt Name gt ON x amp EP
179. roups one by one or multiplex them into a single string For example the first command line below describes the same ATOM setup as the next three command lines provided the same Group Type Port name and Per is specified in all four command lines PASHS ATM Group type gt lt Port Name gt ON Per amp mm1 mm2 mm3 PASHS ATM Group type gt lt Port Name ON Per amp mm1 shtech PASHS ATM Group type gt lt Port Name ON Per amp mm2 PASHS ATM Group type gt lt Port Name ON Per amp mm3 The receiver stores the ATOM setup independently for each Port Name This means for example that users can enable a PVT message on virtual port Z and physical port A simultaneously and generally with different periods and sub blocks When configuring the ATOM setup each new setup command adds or modifies particular settings to the already existing previous setup but does not reset it That is why before requesting a setup update it may be convenient first to disable all the ATOM outputs using the following command PASHS ATM ALL Port Name OFF Any command in the form PASHS ATM Group type gt lt Port Name gt ON will initialize the corresponding default ATOM Group setup for Port Name Currently the following sub messages sub blocks are supported ALR USR DBG SUP CPI EPI CVE EVE PVT COO ERR VEL CLK LCY HPR BLN MIS ROT BSD PRR SVS LDP CDC LMP ATR ANM RNM UEM AOP OCC SNS M
180. rs are available antenna connector refers to so called external antenna and can process L1 L2 signal while antenna connector 2 refers to so called internal antenna and can process L1 signal only For other future Ashtech boards there can be other relationships but user Manual for each board exactly specifies what antenna connector index refers to The antenna name which is generated in ATM ATR ANM message always refer to antenna corresponding to connector reported in this header The complete status of each potentially available antenna is supposed to be seen via other message see ATM STA AST Usually all the data corresponding to the same antenna ID engine ID and request ID are generated within single PVT message i e all blocks under the same header However for some hardware targets and firmware versions position data corresponding to the same IDs can be spread over more than one transmission In this case M bit is set as described to help PVT listener to compile complete PVT epoch corresponding to particular set of antenna ID engine ID and request ID ashtech Primary Time Tag Time Tag Time Tag extension type extension Full BF Fine Time Tag Time Tag Depends on extension type Figure 3 4 b Time tag organization Table 3 4 b Time tag presentation Data item Bits Data type Offset Scale Range Comments DF Number GNSS time modulo 1 hour 4095 means Primary time tag 12 uint12 0 1 s
181. ry parameters These are the data that usually change slowly and accompany position sub block COO information To save throughput this sub block can be requested at a lower rate than the position sub block Output Logic on time Sub block Binary size 23 bytes 184 bits How to request PASHS ATM PVT lt Port Name gt ON x amp MIS Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also GPGGA GPRMC GPZDA Table 3 4 8 a Sub Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Set to 23 Block ID 4 uint4 8 0 15 Set to 8 Site ID 32 char 4 12 The same as in PASHR PBN message 0 Antenna reference point 1 L1 phase center Position point 3 uint3 44 0 7 2 5 Reserved 6 Ground mark 7 unknown Reserved 2 uint2 47 0 3 See Appendix G AF006 Antenna height 16 uintl6 49 0 0001 m 0 6 5535 Value 6 5535 means 6 5535 DF028 Datum 1 Bit 65 0 1 el 1 custom Default datum RM 6 uint6 66 0 63 63 if not defined or invalid DFO21 clarification Geoid height 16 int16 72 0 01m 327 67 327 68 if not defined or invalid The number of GNSS 12 uintl2 88 0 4095 For GPS wn modulo 4095 cycle time cycles ashtech For GLO day number of 4 year period DF129 4095 means underfined or invalid GPS UTC t
182. sage type 9 uint9 55 0 511 ibiscnesace sei ta 11 MESSAGE DATA The port socket original data come from Source identifier 16 uintl6 0 65535 65535 means no source defined Reserved 16 Bit16 0 65535 Set to 0 0 8 uint8 0 255 Incremented with each new data portion corresponding to the same source identifier Specifies original data packing method 0 Original binary data of data 6 0 63 1 Inverted original binary data 2 Adding number 2 to each byte 3 62 reserved 63 unknown type of packing The length of data in bytes which follow Length of data X 10 uint10 0 1000 Length gt 1000 is invalid The spied data themselves Each byte is The data 8 X char X converted with of data packing algorithm END TRANSPORT CRC 24 uint24 24 bit Cyclic Redundancy Check Total Table 3 7 5 b Examples of adding number 2 Original byte Converted byte 0x13 0x15 OxAF OxBl OxFE 0x00 ashtech OxFF 0 01 Table 3 7 5 c Source identifiers Code Source description Comment 0 Port A The data from physical port A are packed 1 Port B The data from physical port B are packed 2 Port C The data from physical port C are packed 3 Port D The data from physical port D are packed 4 6 Reserved for other physical ports 7 Port H In MB100 refers to internal heading mode pipe 8 22
183. sages 1 18 Nov 19 2010 A number of misprints indicated by System Test fixed Field AF003 clarified for invalid position Appendix Sat health indication is added to RNX message Some details of receiver clock estimation steering clarified in section 2 5 Local meteo parameters message added to ATR group ushtech asntecn Carrier shift message added to ATR group APIS message added to PVT group GNSS clock offset message added to STA group Sat health message aged to STA group Some MSM related changes are added to ATM RNX and some additional clarifications are given Section G 3 is introduced in Appendix G New signals definitions added to signal Mask Appendix E 2 01 Jan 24 2011 The size of Sat and Signal mask is increased which led to reporting ver 2 in headers of ATM RNX and ATM PVT messages See also Appendix E Few extensions clarifications are given for some ATM RNX fields Field AF002 adds 2 more choices Field AF017 introduced Antenna height field added to STA RSP message ATM MES description removed but section header is still kept Some CQ fixes reflected 2 02 Feb 28 2011 Few misprints corrected The description of ATOM version switch command added The description of standard and fine resolution is added to ATOM RNX The difference between v 1 and v 2 was better clarified in the text and newly created Appendix H Galileo Ephemeris message updated but it is still not finalized
184. satellite Frequency Channel 5 uint5 82 0 indicates channel number 07 Number 1 indicates channel number 06 13 indicates channel number 6 31 indicates invalid channel number Health 1 87 GLONASS almanac health DF104 0 GLONASS almanac has not been DF105 received GLONASS almanac health is not Almanac health a 1 bitl 88 available availability 12 GLONASS almanac has been received GLONASS almanac health 15 available P1 2 bit2 89 P1 flag see GLONASS ICD DF106 Hour 5 uint 91 The integer number of hours elapsed since DF107 the beginning of current day Minutes 6 uint6 96 The integer number of minutes DF107 Half 1 bit 102 The number of thirty second intervals DF107 MSB of B word 1 bitl 103 GLONASS MSB of B word It contains the DF108 ephemeris health flag P2 1 bitl 104 P2 flag see GLONASS ICD DF109 Time to which GLONASS navigation data DF110 Tb 7 uint7 105 900 are referenced Velx 24 intS24 112 2791000 GLON ASS component of satellite DF111 velocity vector in PZ 90 datum Posx 27 intS27 136 21121000 GLON ASS ECEF X component of satellite DF112 coordinates in PZ 90 datum Fm 5 intS5 163 2301000 GLON ASS ECEF X component of satellite DF113 acceleration in PZ 90 datum Vely 24 intS24 168 2791000 GLONASS ECEF Y component of satellite DF114 velocity vector in PZ 90 datum Posy 27 intS27 192 2 1000 GLONASS ECEF Y componen
185. semi Wna 8 uint8 240 1 0 255 Almanac week number Toa 8 uint8 248 as Reference time of almanac Health 9 uint8 256 The satellite health information Reserved 7 bit7 265 Set to 00000 END TRANSPORT CRC 24 uint24 272 24 bit Cyclic Redundancy Check CRC Total 304 ushtech The value of Ai generated from field io Inclination Angle at Reference Time from BDS Ephemeris data is scaled by 0 1 and 0 3 6 13 Message GPS ionosphere and time shift parameters This message contains GPS ionosphere and time shift parameters For detailed information about these parameters please refer to the ICD GPS 200 document Output Logic on time on change on new Message Binary size 32 bytes 256 bits How to request PASHS ATM NAV Port Name ON x amp GIT Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also PASHR ION Table 3 6 13 a Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message Length 10 unt10 14 Message length in bytes Set to 26 for this message MESSAGE HEADER Message number 12 uintl2 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set
186. sing RNX as differential data generated by moving receiver The accuracy indicator of reference position can be also provided With multiple GNSS tracking the definition of receiver clock offset and clock steering must be clarified Internally receiver can estimate own clock offset against each of available GNSS time scales Each epoch some GNSS is selected as primary Primary GNSS can affect up to e time tag presentation for some messages e default datum for output position reference time system when generating receiver clock offset estimate and making clock steering Receiver clock offset estimate generated in PVT and RNX messages always refers to primary GNSS system specified in the header of these messages Clock steering procedure applies this clock estimate equally to all GNSS observables Receiver clock estimates against all GNSS scales receivers currently supports are output via STA messages group shtech shtech 3 MESSAGES DESCRIPTION This chapter contains the detailed bit to bit description of messages supported by ATOM format ver 1 2 A short summary of principal differences between 1 and v 2 is provided in Appendix H The following ATOM groups are described e Positioning results ATOM e Attributes data Navigation data ATOM NAV Raw binary data ATOM DAT GNSS observations ATOM e Supplementary data ATOM SUP e Status information ATOM STA Events informat
187. t Name ON x amp GFT Permissible intervals x sec 1 2 3 etc each integer second but less than 999 See also RTCM 3 MT 1013 Table 3 6 14 a Message structure and content ashtech Data item Bits Data type Offset Scale Range Comments DF Number START TRANSPORT Transport Preamble 8 uint8 0 Set to 0xD3 HEX Code Reserved 6 bit6 8 Set to 000000 Message 10 nati 14 Message length in bytes Set to 10 for this message MESSAGE HEADER Message number 12 uintl2 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 5 is reserved for ATOM NAV message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 5 Specifies which message follows For message type 9 uint9 55 0 511 this message s t to 22 MESSAGE DATA 0 DF004 TOW 20 uint20 64 604799 sec GPS time of week WN 12 uint12 84 0 4095 week GPS wn modulo 4095 cycle ashtech 4095 means underfined or invalid GPS UTC 6 uint6 96 0 63 sec GPS UTC time shift 63 means unknown DF054 Reserved 2 bit2 102 Set to 00 END TRANSPORT CRC 24 uint24 104 24 bit Cyclic Redundancy Check CRC Total 128 3 6 15 Message GAL ionosphere and time shift parameters This message contains Galileo io
188. t of satellite PF115 ashtech coordinates in PZ 90 datum 5 intS5 219 2391000 GLON ASS ECEF Y component of satellite DF116 acceleration in PZ 90 datum Velz 24 intS24 224 2791000 GLON ASS ECEF Z component of satellite DF117 velocity vector in PZ 90 datum Posz 27 intS27 248 21111000 GLONASS ECEF Z component of satellite DF118 coordinates in PZ 90 datum Adoz 5 intS5 215 2391000 GLON ASS ECEF Z component of satellite DF119 acceleration in PZ 90 datum P3 1 bitl 280 P3 flag see GLONASS ICD DF120 T intS11 281 2 40 Relative deviation of predicted satellite DF121 carrier frequency from nominal value GLONASS M P 2 bit2 292 GLONASS M P word DF122 GLONASS M 1 GLONASS M 1 word extracted from third DF123 1 bitl 294 3 string string of the subframe 30 GLONASS correction to the satellite time DF124 2 ines 295 2 relative to GLONASS system time Time difference between navigation RF DF125 30 signal transmitted 12 sub band and CILONASS M At 2 navigation RF signal transmitted in L1 sub band En 5 uintS 322 1 day The age of GLONASS navigation data DF126 GLONASS M P4 1 bitl 327 GLONASS M P4 word DFI27 GLONASS M Fr 4 iind 328 GLON ASS M predicted satellite user range DF128 accuracy at time t GLONASS calendar number of day within DF129 GLONASS M 11 uintl1 332 1 day four year interval starting from the 1st of January in a leap year Type o
189. t this interval will be ignored ATOM STA messages could be output using change principle i e a message is generated once the content of the receiver data buffer containing corresponding data has been updated i e changed At the same time most users can want to see STA messages with some preset interval and Ashtech implemented this strategy In this case user can miss some internal status updates if more than one internal update occurred between consecutive STA messages Or user can get identical information in two consecutive STA messages if there was no any internal update between them shtech Most of the ATOM messages are output by combining the new on change on time principles For example if the ATOM EPH message is requested at an interval of x 600 seconds then ephemeris data for a given satellite will be output immediately after request new and then in x 600 seconds time etc If new ephemeris data new IODE for this satellite are decoded these will be output immediately change and the counting of the interval of x 600 seconds will start from this moment About NAV messages which serve all tracked satellites it should be understood that such a rule is applied to each satellite independently In order to save the overall peak throughput no more than one NAV message is output over a single 1 second epoch In other words the minimal interval between any NAV m
190. tech Reserved 6 bit6 8 Set to 000000 Message Length 10 and 14 Message length in bytes Set to 43 for this message MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 6 is reserved for ATOM DAT message Version 3 uint3 40 0 7 ATOM version number set to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 DAT message type 9 9 55 0 511 Specifies which DAT message follows For this message set to 3 MESSAGE DATA SBAS satellite number 0 Sat ID is not defined gt PRN 120 Sat ID 5 uint5 64 0 19 2 PRNfH2I 19 gt PRN 138 Type of signal Signal ID 3 bit3 69 0 7 0 Signal is not defined 1 LICA signal Receiver channel number Channel number 8 uint8 72 0 255 0 channel number is unknown Message Type 6 uint6 80 0 63 SBAS subframe number 575 70 1 Receiver time GPS 20 uint20 86 1 sec en defined Reserved 6 bit6 106 Set to 000000 Subframe data 250 bit250 112 SBAS subframe data Reserved 6 bit6 362 Set to 000000 END TRANSPORT ushtech CRC 24 uint24 368 24 bit Cyclic Redundancy Check CRC Total 392 3 7 4 DAT Message Galileo Raw Pages 3 7 55 DAT Message EXTernal port data This message contains the binary data entering the receiver via one of its ports sockets Particul
191. tes shtech MESSAGE HEADER Message number 12 uint12 24 1001 4095 4095 is reserved for Ashtech DF002 Message sub number 4 uint4 36 0 15 3 is reserved for ATOM PVT message Version 3 uint3 40 0 7 ATOM version number set to 1 or 2 1 other PVT message s corresponding to given antenna ID engine ID and request ID will be output for given time tag Muluplemessage bit Ol 0 no other PVT message s corresponding to given antenna ID engine ID and request ID will be output for given time tag Antenna ID 4 uint4 44 0 15 See Appendix G AF019 Engine ID 6 uint6 48 0 63 See Appendix G AF002 Request ID 4 uint4 54 0 15 See Appendix G AF020 Reserved 5 bit5 58 0 31 Set to 00000 Number of used satellites 63 means not Nsats used 6 uint6 63 0 63 defined 62 means 62 Number of visible satellites 63 means not Nsats seen 6 uint6 69 0 63 defined 62 means 62 i Number of tracked satellites 63 means not Nsats tracked 6 uint6 75 0 63 defined 62 means 62 0 GPS is primary 1 GLONASS is primary Primary GNSS system 2 uint2 81 0 3 2 BEIDOU is primary 3 reserved for other GNSS Refers to primary GNSS system time Time Tag 21 Pul scale see tables 3 4 b 3 4 c and 3 4 d MESSAGE DATA Sub blocks of PVT message See sub sections below END TRANSPORT shtech CRC 24 uint24 24 bit Cyclic Redundancy Check CRC
192. thing residual 16 intl6 23 QE pegs aa PO eded to psebdodanse to get unsmoothed value The copy of ashtech MPC smooth correction but with opposite sign Value 20 48 means invalid Value 20 46 means less or equal 20 46 value 20 46 means more or equal 20 46 Reserved 3 Bit3 39 Set to 000 The copy of smooth count Smooth count 8 uint8 42 1 sec 0 255 Value 255 means 255 Br Original channel warnings see Signal warnings 14 6114 50 table 3 8 64 64 Notes Full Doppler j for each Signal j is restored as FullDoppler j RoughDoppler FineDoppler j e refers to the legacy output message PASHR MPC containing GNSS measurement from one satellite for one epoch Table 3 8 6 4 Signal warnings Data item Bits Data type Offset Scale Range Comments DF Number SIGNAL WARNINGS one signal portion 0 zero fractional bias polarity Similar to known polarity Fractional carrier bias 2 uint2 0 0 3 Ep bale cycle tas ute polarity not resolved 2 arbitrary carrier bias 3 reserved 0 carrier tracking is OK Same as MPC pur 2 1 possible carrier drift warning bit 2 0 OK Same as MPC 1 satisfactory warning bits Pseudo range quality 2 uint2 3 0 3 2 admissible 3 4 See notes 3 bad below ashtech
193. to 1 Reference station ID 12 uint12 43 0 4095 Reference station ID DF003 Specifies which message follows For message type 9 uint9 55 0 511 set to ashtech MESSAGE DATA a0 8 int8 64 299 Ionospheric parameter seconds al 8 int8 72 Ionospheric parameter seconds semi circle a2 8 int8 80 ges Ionospheric parameter seconds semi circle 03 8 int8 88 g Ionospheric parameter seconds semi circle po 8 int8 96 2 Ionospheric parameter seconds p1 8 int8 104 gs Ionospheric parameter seconds semi circle 2 8 int8 112 3 Ionospheric parameter seconds semi circle p3 8 int8 120 2 Ionospheric parameter seconds semi circle Al 24 int24 128 First order terms of polynomial AO 32 int32 152 3 Constant terms of polynomial Tot 8 uint8 184 m Reference time for UTC data Wnt 8 uint8 192 0 255 UTC reference week number AtLS 8 int8 200 GPS UTC differences at reference time WnLSF 8 uint8 208 0 255 7 when leap second became DN 8 uint8 216 0 7 en when leap second became MLSF 8 int8 224 between GPS and UTC after END TRANSPORT CRC 24 uint24 232 24 bit Cyclic Redundancy Check CRC Total 256 3 6 14 Message GPS full time parameters This message contains the full set of GPS time parameters Output Logic on time Message Binary size 16 bytes 128 bits How to request PASHS ATM NAV lt Por
194. to some of them are provided Some ATOM data fields are the exact copy of the corresponding standardized RTCM 3 data fields some are unique to the ATOM format That is why ATOM data fields having exact RTCM 3 counterparts are marked as DFxxx For example data field Message Number uint12 4095 reserved for Ashtech is referenced as DF002 If reference to a data field is given in form see DF then it means that described field has something common with standardized DF but does not copy it exactly Some other ATOM data fields which are intended for proprietary use only are referenced as AFxxx where xxx is a unique number assigned to a given field other fields are not marked The description below refers ATOM ver 1 2 Further ATOM versions will be marked with higher version numbers The version number is provided inside each ATOM message header The 3 party decoding equipment should check the version number before parsing the message and make no attempt to interpret it if the detected version number is higher than the currently supported one Generally a higher ATOM version number does not guarantee backward compatibility with the previous versions unless the decoder is updated for the new ATOM version Some ATOM messages contain reserved fields 3 party users should ignore all these fields With ATOM development some initially reserved fields usually defined as zero can become meaningful Since 3 party users ignore t
195. ty to extend are added to Section 2 1 2012 Editorial changes adding missed fields Group DBG is renamed to ALR and described in given manual section 3 12 Two messages are added to SUP group 2 20 Sep 25 Some misprints corrected some clarifications given 2012 2 21 Sep 28 Code misprint cleaning 2012 2 22 Sep 30 Modify valid range and invalid values for number of RNX PVT STA fields 2012 2 23 Oct 12 PVT LMP block modifications added 2012 Message ATM PVT BSD introduced ATM ATR CPB message corrected 2 24 Nov 24 NAV GIT for Galileo and QZSS introduced 2012 Fix bug in NAV GIT tot field ushtech ATM ATR CPB message corrected Remove all GIOVE A B traces Modify PVT COO Field AF023 clarified Remove section G 4 2 25 30 2013 Table Supported NAV messages expanded with GAL and QZS GITs Fix typo gt Fix data types typos and modify structure for NAV GIT for GAL Modify ATM NAV amp GFT ATM RNX ATM PVT amp MIS GNSS time cycles description 2 26 Feb 28 2013 Fix date of 2 24 release Fix ATM NAV amp GFT ATM RNX ATM PVT amp MIS GNSS time cycles modulo value GAL ionosphere offset and message length typos First revision for Beidu Ephemeris almanac ion amp utc message Add Beidu GNSS id for all messages Remove Section 3 3 Satellite Signal and Cell Masks to Appendix I 2 27 Jun 20 2013 number of clarifications with BeiDou is provided in
196. udo ranges Any C L or L L combination is flat provided continuous carrier tracking is achieved Only ionosphere and some other effects can cause slow divergence of one observable against another e Doppler is interpreted as the true carrier phase derivative i e the Doppler sign is equal to the delta carrier sign e Signal strength corresponds to the RTCM 3 definition Carrier to Noise Ratio and is expressed in dBHz the generated observables are raw i e not corrected for any specific e g atmospheric effects In addition the statements below enumerate what corrections are applied or can possibly be applied to original ATOM RNXobservations All the GNSS observables are steered for the same receiver clock value The clock error in all observables does not exceed about 300 meters Some observation messages can provide the value of original clock which can be used to restore original not steered observables e All carrier phases corresponding to the same GNSS and band are aligned with each other i e the possible cycle or other bias is properly compensated for The initial integer count in all carrier phases is set to match the carrier phase and respective pseudo range at carrier initialization epoch e Pseudo ranges be smoothed by carrier phases to reduce the noise multipath error Some ATOM observations messages can provide the so called smoothing residual allowing the unsmoothed pseudo range value to be restored
197. up ALR is very valuable for identifying receiver problems These messages are supposed to inform end user about receiver problems or incorrect setups Each available for end user alarm supposes clear set of user actions to restore normal receiver operation These messages are parts of Ashtech Trouble Log so called atl log file which customer can request from any Ashtech receiver in case of problems Group SUP contains various data needed mostly to supplement position and raw RNX data for some specific applications There is a special group 4095 15 which intentionally has no 3 letter name assigned This group is not described in given Manual This group is a simplest packing frame to encapsulate any other non RTCM 3 message for special applications In future ATOM is open to adding more groups to the currently supported list Each group contains a number of particular sub messages sub blocks which can optionally be enabled or disabled Each group has its own default configuration which can be receiver type and firmware version dependent Some ATOM messages have fixed length some others have variable length Variable length can be caused by the fact that this message contains multiple satellite information i e Nsat dependent On the other hand variable length can be caused by some internal switches in the message header defining different presentation forms for the data that follow Most of the data ATOM generates are extracted from
198. ustom datum clarification block There is no guarantee that reported differential position is tagged to default specific for GNSS system selected as primary datum even it is claimed so In fact the datum will be defined by the datum reference position is expressed in There are evidences that some providers generate reference positions tagged to local datum w o explicit specification of this e g some Network providers in US generate reference position in NAD83 without any mentioning of this ashtech This sub block refers to the data presented in the position COO sub block described above It contains parameters allowing the complete position covariance matrix symmetric positive definite to be restored When reporting differential RTK DGPS position accuracy it is assumed that base coordinates are 100 accurate 3 4 ATOM PVT Message Sub Block Accuracy message sll 512 513 5 522 523 where 511 522 and 533 are always positive other terms can be negative s33 Here indexes 1 2 and 3 refer to latitude northing longitude easting and altitude up components of position baseline respectively Output Logic on time Sub block Binary size 10 bytes 80 bits How to request PASHS ATM PVT lt Port Name gt ON x amp ERR Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less than 15 min See also GPGST Table 3 4 2 a Sub Message structure and cont
199. which follow Subframe data K bitK 112 Frame data themselves END TRANSPORT CRC 24 uint24 112 K 24 bit Cyclic Redundancy Check CRC Total 136 K Note proper number 0 to 7 of zero bits is inserted before CRC to make complete message to contain integer number of bytes Only data which were successfully synchronized decoded are generated numbers representing Satellite ID and Signal IDs respectively refers actually to the position rank of corresponding bit in Satellite and Signal Mask see Section 3 3 E g ID 0 refers to the first bit in corresponding Mask ID 1 refers to the second bit in corresponding Mask etc 3 8 RNX M ashtech The ATOM RNX RiNeX message is intended to generate receiver observations to allow their future effective unambiguous conversion to RINEX 3 In most cases this message can also be used as differential protocol between RTK base and RTK rover The RNX message can contain observables from more than one GNSS and optionally receiver reference position stationary or moving The RNX message can be customized using the existing serial interface Customization may range from fully expanded to fully compacted allowing users to select the desired tradeoff between message size and data availability The RNX message supports the generation of different GNSS as well as reference position inside separated ATOM transmissions as well as inside a single ATOM transmission The description below is f
200. x amp VEL Permissible intervals x sec 0 05 0 1 0 2 0 5 1 2 3 4 5 6 10 12 15 20 30 60 120 etc each integer minute but less 15 min See also PASHR POS GPVTG Table 3 4 3 a Sub Message structure and content Data item Bits Data type Offset Scale Range Comments DF Number SUB BLOCK DATA Block size 8 uint8 0 0 255 Set to 12 Block ID 4 uint4 8 0 15 Set to 3 X velocity 25 int25 12 0 0001 m s u en 1677 7216 if not defined or invalid Y velocity 25 int25 37 0 0001 m s M 2 1677 7216 if not defined or invalid Z velocity 25 int25 62 0 0001 m s Ws 1677 7216 if not defined or invalid 2 0 instant velocity Velocity type 1 bitl 87 0 1 1 mean velocity 4 uint4 88 0 15 See table 3 4 3 b smoothing interval Reserved 4 bit4 92 0 15 See Appendix G AF022 Total 96 ashtech Table 3 4 3 b Mapping table for velocity smoothing interval Smoothing interval Effective interval sec Comment identifier 0 0 Refers to instant velocity computed with rough Doppler 1 0 0 005 2 0 005 0 01 3 0 01 0 02 4 0 02 0 05 5 0 05 0 1 6 0 1 0 2 7 0 2 0 5 8 0 5 1 9 1 2 10 2 3 11 3 4 12 4 5 13 Reserved 14 Reserved 15 No interval defined Notes e Instant velocity refers to the true estimate of the position derivative for a given time tag as opposed to mean velocity which refers to the est
201. xtended observation data Serial interface related with REF block of ATOM RNX BAS is added section 4 5 Notes regarding cycle carrier alignment pseudo range smoothing and clock steering are added for ATOM RNX Clarification of Sat usage and diff status flags in ATM PVT SVS Intermediate changes in ATOM BAS message description still not finalized Some editorial changes done in different parts of the Manual New group EVT section 3 10 added corresponding changes are added to other sections ATOM PVT TTS message is moved to EVT group Some fields AFxxx description is moved to Appendix G The description of ATM HED is moved to Appendix G Appendix H removed 1 06 October 23 2009 Accepting all the previous changes Fixing misprints Syntax changes towards releasing the Manual for user Additional clarification of some fields and serial interface Words GNSS platform MB500 etc are removed ATOM Logo added PASHSQ ATM PAR described in Section 4 ATOM ATR SNS message removed Antenna type AF006 field description is moved to Appendix G Appendix G is reformatted Some fields in ATM ATR OCC AOP are clarified Section 3 10 is reformatted 1 07 November 2 2009 Style changes and clarifications Reference documents updated The description of ATM RNX serial interface simplified The description of ATM RNX BAS customization re fined 1 08 December Fields AF007 and AF008 are put to Appendix
202. y following elevations for all visible satellites Here visible satellite is designed as each which is currently tracked can have negative elevation in some specific cases and any other which is not tracked but is above horizon in correspondence with latest almanac Sat correcting status field informs users if differential corrections are applied to a given satellite e g DGPS SBAS etc ashtech least one observable of a given satellite is used in position then this satellite is considered as used Otherwise it is considered as not used Sat correcting status and Sat usage status fields are quite independent of each other A satellite can be corrected but not used in position or vice versa Table 3 4 12 d Signal data Data item Bits Data type Offset Scale Range Comments DF Number SIGNAL DATA SNR uint6 Ncell 1dBHz 0 63 dBHz Set to 0 if signal is not tracked Ncell times 8 Set to 0 if signal is not tracked Smooth count Ncell times uint8 Ncell lsec 0 255 sec 255 means 255 0 quality is not defined 2 1 good quality Quality status Ncell times bit2 Ncell 77 2 medium quality 3 questionable quality Total 16 Ncell Notes is the complete number of available signals It is equal to the number of 1 in the Cell Mask field Each particular field uses internal looping e g the SNR field includes sequential

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