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Z12 RTK Supplement

1. JE oin Press e to change NO WEST SOUTH MENU NORTH EAST YES EG ETE ETE e TE e Figure 8 Screen 9 Site and Session Control Press e to activate the cursor Enter the 4 character site ID of the base in the SITE field Press e again 13 Real time Z Supplement Set Up the Radio NOTE The following setup is applicable only to the Ashtech data radio 3 Go to Screen 4 by pressing 4 Press e and move the cursor to select the MODEM sub screen Press e to display the Modem Setup menu Screen 4 Modem neue Menu PORT 8 TYPE Ai Press 1 to setup 2 to view last setup to change e to enter c to cancel NO WEST SOUTH lt MENU gt NORTH EAST YES foo o ao aaa i Figure 9 Screen 4 Modem Setup Menu Make sure the PORT field is set to B Use or to change it This should be the port you connected the radio to Note that Port B is labeled PORT 2 on the back of the receiver Move the cursor to the TYPE field If necessary press or to change the field to ASHTECH DATA RADIO Press 1 and the display will show PRESS ANY KEY THEN WITHIN 10 SEC TURN THE RADIO MODEM OFF AND ON Press any key for example the e key Within 10 seconds turn the radio off and then on If the radio is off just turn it on The receiver screen will flash a message TEST PASSED and will display the radio param ete
2. Press a v to toggle page WEST SOUTH MENU NORTH EAST YES opa olaa Figure 28 Screen 5 Page 3 CPD Data Link Status for Base See the section below for a description of the display parameters Rover Screen 5 When the receiver is in CPD ROVER mode page 3 of Screen 5 looks like MODE displays the current receiver CPD mode BASE or ROVER INTVL sample rate for QA computation BASE STAT displays the base station status as follows ABCDE where A B C D E PRN lists the satellites PRN ID in the transmitting DBEN message or received DBEN message If the first digit is shown in reverse video P code L1 is not locked If the second digit is shown in displays 1 if the receiver has not tracked the L2 observables displays 1 if the entered position and computed position differ by more than 500 meters in any direction displays 1 if the base station has not computed position using the raw pseudo ranges displays 1 if base station antenna parameters are all zeros displays 1 if the base station coordinates are not entered reverse video P code L2 is not locked DBEN TIME displays current DBEN time base only SETD ID displays the set DBEN message header RCVD ID displays the DBEN message header received The SETD ID and RCVD ID should always be the same 33 Real time Z Supplement CORD USED displays which base station coordinates are used in the PNA
3. such as 1J00 indicate that the receiver has this capability Screen 0 705 08 07 08 09 10 11 12 T 22 31 29 19 18 07 30 28 27 02 16 LK LK LK LK SN LK LK LK LK C TZ PHONE 800 229 2400 FAX 408 524 1500 0 NO WEST SOUTH MENU NORTH EAST YES SEDET EHE EE E Figure 4 Screen 0 To find out more details about your receiver options 10 Real time Z Supplement 1 Go to Screen 4 by pressing 4 Screen 4 POSITION DIFFERNTL SESSION RCVR CTRL PORT A PORT B PORT C PORT D EXT FREQ PULSE GEN DATUM MODEM SUBCMDS PHASE DIF MESSAGE Press e to change 2 SOUTH lt MENU gt NORTH EAST YES EXJBISEYSIETEETE Figure 5 Screen 4 2 Press e to enter edit mode Using the arrow keys select the SUBCMDS menu item Press e again to enter the SUBCMDS screen Screen 4 Subcommands Subscreen Code of command e to enter c to cancel z Tj an E ET EAST YES H Figure 6 Screen 4 Subcommands Subscreen 3 Enter 888 in the CODE OF COMMAND field and press e The receiver configuration 11 Real time Z Supplement will be displayed Screen 4 Configuration Identification Display S N 700845100000 al OPT DP12MX LJ SLP SO 11 04 94 12 38 NAV 1J00 04 28 95 22 44 MCF 62 CHN 1063 11 09 94 12 57 CFG 2L ZL NO WEST SOUTH MENU NORTH EAST YES Og ES TE ESTEE E HE TE
4. POSITION DATA SELECTION SOLUTION PARAMS THIS COORDINATES ADVANCED PARAMS OTHER COORDINATES NO WEST SOUTH lt MENU gt NORTH EAST YES EEn Figure 16 Screen 4 Carrier Phase Mode Selection Subcreen 10 Use or to change the first field to ROVER If the port setting is not correct move the cursor to the PORT field and change it 11 Press e to leave the PHASE DIF subscreen High Speed Solution Computation The Quick Measurement option Q provides the Real Time Z user with the ultimate high speed accuracy A Z 12 configured with the Q option can output new independent solutions at 1Hz 2Hz and 5Hz with extremely low solution latency typically 100 to 125 milliseconds This fea ture makes the Real Time Z ideal for navigation and machine control as well as other dynamic applications which demand high speed performance To verify the presence of the Q option in your receiver go to screen 8 and enter the command 888 The response message will display a field entitled OPT which lists the configured options The following section provides the necessary information to generate 2 and 5Hz solution computa tions for those users who have the Q option installed 21 Real time Z Supplement Go to screen 4 highlight the RCVR CTRL field and press Enter Screen 4 Receiver Control Z MODE A CHAR ACK Y to change NO WEST SOUTH MENU NORTH EAST YES
5. Figure 7 Screen 4 Configuration Identification Display For a receiver capable of real time centimeter level positioning the last character of the options field should be J where J indicates the Real time Z mode option Press e to return to Screen 4 If you want the display backlighting to remain on go to the SUBCMDS subscreen as described in step 2 Enter 101 in the subcommands field and press e but remember that backlighting draws an additional 2 watts from the power source Press e or any other key again to return to Screen 4 Reset the Z 12 Receivers Prior to setting up the Z 12 receivers for Real time Z mode operation for the first time it is wise to reset the receivers to their factory defaults To do this perform the following steps l 2 3 Turn off the receiver if it is on Press and continue pressing 4 while turning on the receiver After a moment the receiver displays a message requesting you to press YES within 10 seconds to reset the internal RAM the setup parameters Press YES or 8 to get the internal RAM test display The following message is displayed after com pletion of the internal reset Testing NAV board internal RAM NAV board internal RAM test passed Push any key to continue Pressing any key except gt returns you to Screen 0 Note If your receiver does not have data storage capability skip the next two steps If you want to also reset the d
6. No pool ee Mas lt HENU gt NORTH EAST YES EX 4 a 9 Figure 11 Screen 4 Carrier Phase Mode Selection 12 Use or to change the first field to BASE If the port setting is not correct move the cursor to the USE PORT field and change it Enter the Base 13 Station Coordinates Move the cursor to the THIS COORDINATES field and press 1 to display the This Sta tion Coordinates subscreen 16 Real time Z Supplement Screen 4 This Station Coordinates Subscreen 00 00 00 00000 N 00 00 00 00000 W 0000 0000 M 00 Fed aam 0 0000 M 0 0000 M 00 0000 M 00 0000 M NO WEST SOUTH MENU NORTH EAST YES oan gunu Figure 12 Screen 4 This Station Coordinates Subscreen 14 Enter the WGS 84 position of the base station the antenna height and any offsets If you prefer to enter the base station coordinates in degrees minutes format enter them on the first line of Screen 4 Press e twice to save the changes and return to Screen 4 This position will now be displayed both on Screen 4 and on the THIS COOR DINATES display of the PHASE DIF subscreen At this time you should see the STATUS light on the base radio flashing green every second as it broadcasts the DBEN message If the position you enter is incorrect or the receiver s computed position differs by a large amount the position display on Screen 4 will flash to alert you of this situation A beep wi
7. RECEIVER CONTROL MENU CYCLE TIME 0 50 SEC e to enter The last field in the RECEIVER CONTROL MENU is entitled CYCLE TIME and controls the solution computation rate The default with the Q option installed in 0 50 seconds 2Hz To change to 5Hz enter 0 2 The receiver will power cycle after this command is sent so it is a good idea to save all current settings before changing the cycle time The following table summarizes the relationship of the CYCLE TIME settings to the raw data recording interval INTVL and to the real time output rate send interval HEHEH Figure 17 Screen 4 Receiver Control c to cancel Table 1 Cycle Time vs Raw Data Recording Interval Cycle Time with Q Option Raw Data Interval Real Time Output Solution Update Rate 1 0 50 0 20 Note Raw data collected for post processing purposes must be recorded at a rate of 1Hz or slower Data collected at a 2 or 5Hz rate cannot be post processed 20 seconds 0 50 second 0 20 second Save the Setup Parameters 5 0 seconds 0 5 second 0 2 seconds 22 1 Hz 2 Hz 5 Hz Real time Z Supplement 12 In Screen 4 move the cursor to SUBCMDS and press e Screen 4 Subcommands Subscreen ajaja e to enter c to cancel NO ala SOUTH MENU Fel EAST YES c Figure 18 Screen 4 Subcommands Subscreen 1
8. I SS M cec DEN M DEM E 22 Gomiputed CAM Zanten eaten aut sue nd od dede a oa tad als cele 37 COMPUTE di see utem aat t cutem Aes NN 17 CONFIO cado iicet inc Did beta eben bd Libor du aS uU deta ed and 47 configured pios c5 oe A uate ae napa iq tesi tsp Re ces tue 21 COV AIAN CS Irene hui on mA tme e are At a dorm e eed den 36 CPI MANE SS a ead 1 CPDsetup parameter tee settee cat eeen dd a li 23 49 Real time Z Supplement Current POSITION serene tacta dba ca d a ON OR eir ede IRR 46 Cycle integer amblgliitles usa ladra da thun aM Gc bad a e at a ce dan 1 D datasdropsOUt venten ete AS 40 data link LOS ted tort ade pee datis eade E Oene eben 35 DATA link Speed iae eet ea en db rra ie td tb star dede i ine vada 20 42 datalog SCR rt ls 35 da tiis ood tei dee enean A UR me di MC 28 DB EUM fo ale id cu cQ Pe ee 1 4 8 29 HELU parameter S qe en es chaos wees ve tee ite niat pA uf ON 47 detault Settlmge sc oo Gud adito do Me tie Gta lei seq eerde oet i gs 40 ditfere tial correction s oae edge hi uide ts dn A ias taan 1 differential data link venne ARES 8 DEC onenn eee en 29 DEF EE 29 d uble difference senad alee arash an cun tesis tem iem oc Ue oan tating 1 dOWAIG AMD A A A ida 46 dytiamieODetatloti A e 36 E Es a AL Usu NR MODE CM SM c EAM LC LA pM ae 28 edit MOE oos ee eo D RR WI dee e rp vae aA RER 11 Si 5E MR n 41 Us isa 44 entered COS soos oan e e ate o eese Ce posl a EMT 37 BOE c Ri a Ud E Em een Re sled LE 47 external ANE
9. OUIUDUEL o eae dr hr e freed ao cie dete heee 36 TROUBLESHOOTING resia ea AS 37 Rover doesn t show E ias cuo ets ere Mo D RA eR qM m aM M 37 Base doesn t show Screen 5 CPD Data Link Status page 37 Real time Z Supplement Base CPD Data Link Status page doesn t show PRN numbers sss 37 Base beeps and Screen 4 position flashes nnn erneer enneenseerseeenneeneerseeenn 31 Base data radio status light isn t blinking every second annen evene enne ereenn 37 Rover data radio status light isn t blinking every second nennen eneen 37 Base station status on Screen 5 is not 00000 anneer eenen enne enseerseenn 38 Position is not updating on rover Screen 20 sse 38 Screen 20 doesn t update every second or beeps and flashes OLD 38 Screen 20 only shows float solution eee tt eere aded tene eden 38 Real time Z solutions are not being stored in the rover 38 SYSTEM PERFORMANCE OPTIMIZATION eese nennen 39 CPI Solution Parameters an e tetas DNE Cu cu Dd cae MA UE LE 39 PD YIANNIS sac escis i Se clases haelen IR UE Dreekes 39 ln M 39 Mi cod oe PR e ghe en ub etia di teni a e a detras i Spe UM ea 39 Past CEDE us ecce dd t e ted tat stage EE e eee 40 Base POST ea M d e RU UE 40 PAT TOG Br Modei nn ccc acest fti a tee ca eed adn tut toe Leeds 40 Hacc P de 41 DBEN Message In
10. The base station radio shown in Figure 1 operates in the 450 MHz to 470 MHz frequency range UHF Since UHF communication requires line of sight between the base and rover receivers the base radio antenna should be mounted as high as possible to allow the rover station to receive the GPS measurements from the base station at longer distances However this needs to be bal anced with reasonably short radio antenna cables due to the relatively high cable loss at UHF fre quencies A length of 15 feet is used for the Ashtech base radio antenna cable Note that co locating the base radio antenna and GPS antenna will not cause any interference problems since they operate at different frequencies UHF versus L band Detailed specifica tions for the base radio and its amplifier are given in the Base Radio Manual Rover Station Configuration The rover station can be utilized in various configurations including man portable or vehicle mount systems A typical rover station setup is depicted in Figure 2 Real time Z Supplement Rover Radio Antenna P N 103711 Z 12 P N 700845 GPS Antenna p P N 700700 mn Pd T ED E Antenna Cable Mag Mount P N 103712 GPS Antenna Cable P N 700265 or 700255 Rover Radio P N 700836 Hadio Cable 1 0 Data Cable Ryn 700968 P N 700617 Battery Cable P N 700867 To external processing computer 5990 o S ASHTECH 8861B B
11. and all parameters are at the factory defaults perform the following steps Set Up the Radio NOTE The following setup is applicable only to the Ashtech data radio In Go to Screen 4 Press e and move the cursor to select the MODEM subscreen Press e 18 Real time Z Supplement to display the Modem Setup Menu Screen 4 Modem Setup Menu PORT 8 TYPE Press 1 to setup 2 to view last setup to change e to enter c to cancel NO WEST SOUTH MENU NORTH EAST YES ooo oa aaa Figure 14 Screen 4 Modem Setup Menu Make sure the PORT field is set to B use or to change it This should be the port you connected the radio to Note that Port B is labeled PORT 2 on the back of the receiver Move the cursor to the TYPE field If necessary use or to change the field to ASH TECH DATA RADIO Press 1 and the display will show PRESS ANY KEY THEN WITHIN 10 SEC TURN THE RADIO MODEM OFF Press any key for example the e key Within 10 seconds turn the radio off and then on If the radio is off just turn it on The receiver screen will flash a message TEST PASSED and will display the radio param eters If the receiver displays the message CANNOT CONNECT TO RADIO MODEM check your cable connections and radio power source Also check the PORT field on the Modem Setup subscreen and the baud rate in the Port A or B Setup subscreen If the message BAD CHECKSUM WAS RECEIVED is dis pl
12. messages between the base and rover stations The Message subscreen is accessed via Screen 4 Screen 4 Messages Transmitting Receiving Subscreen MESSAGE VIEW RCV MSG gt 0000 to change e to enter c to cancel NO WEST SOUTH MENU NORTH EAST YES ETE YE E ES IE E Figure 31 Screen 4 Messages Transmitting Receiving Subscreen The message control parameters are RCV MSG enable or disable message reception BEEP enable or disable beep on receiving a message PORT set port for transmitting a message PASSWORD set password to encrypt message If password is different from the message will be encrypted Messages will be received on either BASE or ROVER stations only if the password is the same on both stations MESSAGE the line below this string is intended for writing a message Use 4 to select the character set press the corresponding key Use gt for space If the cursor is in this line and e is pressed all symbols not more than 35 before the cursor position will be sent to the designated port 1524 is the time the message was transmitted in GMT hours minutes format HHMM The field VIEW RCV MSG gt allows you to view the last five received messages When e is pressed at this field the last five messages are displayed 44 Real time Z Supplement REVERSE VECTOR PROCESSING In reverse vector processing RVP the rover station b
13. vehicle magnetic mount Note that this cable has a TNC type connector on one end 4 Connect the rover s radio to Port 2 of the Z 12 receiver using the provided data cable 5 If you are using an Ashtech supplied 12 volt battery connect this to the Z 12 receiver using the power cable If you are using your own power supply make sure it can deliver at least 12 watts of power a minimum of 10 volts at 1 5 amps Turn the Z 12 receiver power switch on ON OFF switch located on rear panel of receiver Warning Never power on a radio without first connecting an antenna to it 6 With the above warning in mind connect power to the rover s radio using the radio Z 12 power cable and turn the power on RECEIVER CONFIGURATION This chapter details how to set up the Z 12 receivers for the base and rover stations for normal Real time Z system operation Receiver screens are shown when necessary Note that not all the setup parameters on these screens are explained here the remaining parameters are explained in the chapter System Performance Optimization Check the Options The receiver type and the firmware version number on the bottom right hand corner of Screen 0 of the receiver indicates if the receiver is capable of performing real time carrier phase differential positioning that is if the receiver can be configured properly for the Real time Z system The receiver type Real time Z and a version number where the second character is a J
14. 2 this device must accept any interference including interference that may cause undesired operation of the device Real time Z Supplement FOREWORD This document is intended to be used in conjunction with the Z 12 Receiver Operating Manual Ashtech document 600224 Rev B You should first refer to this manual to become familiar with the basic Z 12 receiver operation and control The Real time Z functions described in this supplement are in addition to or at variance with the functions described in the Z 12 Receiver Operating Manual All the system components described herein have been certified for operation by the Federal Communications Commission FCC Conventions when using this manual are Receiver keys are denoted by square brackets For example the enter key on the receiver is shown as e in this supplement Receiver messages are shown in all capital letters For example the Phase Differential Subscreen of Screen 4 is given as PHASE DIF Real time Z Supplement CONTENTS INTRODUCTION as o edet Te a Asaph forced od ee Meme a 1 Principles of Carrier Phase Differential GPS cuina iris 1 On the Fly Ambiguity Resolution nice e eset det ee ua edel ae deveined 1 Fast Carrier Phase Dira ri 1 Vector Processing and Reverse Vector Process Midis 2 REAL TIME Z SYSTEM OVERVIEW iiei tzitatilsssene cbacilsblestabesct abb devub M aaies sod obezihan 2 QUICKSTART GUIDE 4d eten 4 Base Station setup DBEN Artsennet ias 4 Rover station Set
15. 3 Enter 555 and press e This will save the user parameters for the rover station setup so that the setup will not need to be performed again after the receiver has been turned off or a loss of power has occurred 14 Press e to return to Screen 4 The setup is complete At this point the receiver will operate in the CPD Rover mode If you would like to optimize the CPD setup parameters for your application see the chapter Sys tem Performance Optimization If this is the first time you are setting up the CPD rover receiver it is recommended that you stop the rover receiver setup here ROVER SOLUTION MONITOR When the rover station s GPS receiver 1s set to Carrier Phase Differential mode see Receiver Configuration chapter you can view the current position solution results and status on the appro priate pages of Screens 2 and 20 These screens are described below Screen 2 Page 1 of Screen 2 shows autonomous position information based on the raw uncorrected 23 Real time Z Supplement pseudo ranges Screen 2 Page 1 02550 121 59 8448E 26 00 M 330 50 Tr 0 50 Km h 1 NO WEST SOUTH MENU NORTH EAST YES Figure 19 Screen 2 Page 1 For page 2 of Screen 2 the ENU velocity and waypoint navigation information uses the CPD position solutions 1f the receiver is in CPD ROVER mode Otherwise the raw uncorrected pseudo ranges are used Position information in this page and al
16. 7 DAME A et vm ta e aa wag Pelo i diente Qa 1 OEP UE A O deden elata efus ho umi Sad de 22 36 P password MD TR 44 PBEN menne AAA A nea 36 A sia cua daniadia ck fsck asia acs pdSen wanna eo anced actin ob ewe so nas aes oio ara eee 4 PIDOD cette cc sal nce a ath oS cc tie A 1 17 36 phasccre sidus uA set dE Cs CE EL NL i ate 31 QM M 29 A ED sanded pea E M ne maie E 29 av 1 28 position ESTIMATION EROL asus Inge api as disk ise 32 position BORON dde 1 28 POSITION soho A a eee ao a o ale Deut e ure 1 position DA a ed LM LE 6 post precessIfg LA A An 1 A mtd let hd eod LC EI ct t atria LI dep DE e EE 3 power on SequetiQe o esee ee ratio edes t e tn devi c due erp ice oan ats pea 5 PRISMEERANSBER o Odo 35 46 program ci AA qua inus ete Lot DEM e RUN OE idees 20 pDseudosrange eos on Lad ast e Ot aNd I LACE 1 29 A1 42 46 51 Real time Z Supplement Q CODO uote del Ned ual al nla st 21 quick measurement ODLOIT ste cf vao ev e E ote ais eode adea yid 6 R PATO data Ink 5 assenaar tai bass AR EN BAR RU aS 1 radio I REED 2 40 facto nedelandse Neo m t Anu CE 40 RAM E e vista eas ages Roast ES hte em neato 13 38 RAP M 31 taw data eet AMNES Sebago M GUERRE ETUR AEN 1 COPOS IIA A qua A FIIV GI A Aa dee ies 36 37 receiver setup Parameters cei ecco ceres ud cbe ao e eed trn kal end 35 TE TRAIAN Vics ch ees eite Si ma etd Cat aetna set pe
17. H SST teder damen kane 36 ERE RARE P Nen deken vele danae nen deere T 35 44 Numerics EEE RR 18 23 SON atra auem MINH MINIM E IU e LEE 11 21 37 A A A SET a NE E EIN dees 1 6 8 40 45 adjustment programi ono E D M P ecu 35 almanaez vA AEN eee ee tei nere 5 6 7 atmb19 titles Su metet qub i ber edi te eirca seu tent breien del 32 40 antenna CODES aieo Rc remet antec ont incaute Po odas des a dol 7 antenna heights A hae AERE OR aes nd d eh OUS AAR bert dert UNE 17 antenna LOCATON SS pr ssa ere eiu set EU 9 antenna offset cb ssec destruit eel tutae diede etd cs suum At Es rd 45 ATUL CTV TUS tedeschi etende enter 46 PO Nr PN 36 a to differ ntial modem eei tet oed e oce doe ete ae Cate aorta A CU 8 autonomous AA AE ene ede dee tes slaty alat Gell ple euer eid T ed e enne 8 45 B backlighting E Gu redo dap dde dut ese tas er idc bd p UN des 5 DASE GATES Pararaton beidt banda tias hehe opa taies dot ade hace hl stus 37 b s t dio sata veda orbis te Eet deta edentate 3 base station coordinates ussen eene E neret see esaet eter a ses e eadeni nan 5 17 bases dent Ss o ace oe tee so teeta vaste aah eed Seats use to m se thas euin 40 a e 3 Balesan E da rei ecc E eed te nn 36 46 DIAEA AUR 36 broadcast BEN Sue udis cuero pio iae Gef otc mu eA I Tries Te aA opua cd 17 C cable TOSS eco epp se a S SE estes ides aces ed ea coo ead 3 carrier phase tt TM DM rU 1 10 29 A eN Medi t m dme M diris c Net ec Ate 36 Conen AA O 8 A A UD ED ma
18. MOON casus on oe S edu Aa eeu ese RN 35 A E 13 F actora bte ense o actu 5 6 13 PUE dca MEL See UT e See He 4 BBC orco ade ec A A ua e um ME eas 47 Tile TAIN AE oca vot tenete el bap a Dan temen MR nde idu UU png e peu t a a dU 35 float CPDsol tiot merendeel a Bese teet AD EQ ORT ard 32 Format A anssen i tasted a situa tn 8 FORA and eset etse eenen Made kea ded Oo eee a ae 8 Irequency Mee nsee oua le ue e e eue oo 0d 20 G GPPS HOSE isetusmodueutaumetidee duit dna manen duis dados e didus 35 46 H EOS Ee 35 46 IEEE Tos 36 independent solutions AA at dane Qe tea O eea betaande 21 IIS GUI nnn ane a edes 42 i t rnal memory reset zita gusce testo dvi Ortho D Usted g ved Eoi nus 8 50 Real time Z Supplement K KUM MATIC Survey p oo acest aie cedet aloe nad Ium Lu D Nes MUN LM EM 1 L RN 41 Tra ala 41 A MMC PE 3 least squares N tWOrk a o ad sc o a a a nebe 35 licensed radio frequency A aaa 6 Itti oF SIDE ca dee as 38 Inest SIGN oe et tak oa e qute A ena s rna De ad 3 42 l ss OT POWER mern cuve itr tener Dated dtes e eit vu ida a dard unida ett dede Rs 18 M irac HB O E AA 2 meas rement delay 2 su iae tere iau est ripe dde is pa bien 40 A neren oa ae OLD Ru teer Des 9 OCA odas acero in Asta tan e mee re nu es t td pd epa 3T N TV IBatlOTE cias id lA 2 NMEA sos 36 37 46 O OBN Gua SAU nM UN e E eee eae ILE MMC SAM I MEUM LAU 36 ODSIEUGHOS van esie a ta RM E PM m dE 3 OELSE cesan 1
19. N message can be logged via Ashtech s DATALOGR program The PBEN message output rate is controlled via the Screen 4 INTVL parameter The 0 5 second output rate is not available for Real time Z since the CPD solution is computed once per second If you want the raw position to be placed in the B file data and output to the serial port change the PHASE DIF solution parameter to OUTPUT RAW POS A new CBEN message has been added to provide more complete information on position veloc ity solution status position RMS and covariance number of satellites and PDOP The CBEN message can be output in ASCII or binary format The binary format is bitwise packed and is not IEEE format compatible The output control for the CBEN message is the same as that for PBEN If for any reason the CPD solution cannot be computed for an epoch there will be no CPD solution output for that epoch in any real time VTS or NMEA message Other new messages have also been implemented These message are only available for query they cannot be set to output periodically like PBEN or CBEN messages These new messages are UBN and OBN The UBN message gives CPD position velocity and statistical information in binary format The OBN message gives CPD vector and site information in binary format Refer to the Real time Z System Integrator s Reference Manual Ashtech document 630001 for detailed command format and message content 36 Real time Z Supplement TROUBLESH
20. OOTING The following problems are sometimes encountered by users new to Real time Z If your system isn t working properly please refer to this list starting at the top If you need further assistance please call an Ashtech customer service representative Rover doesn t show Screen 20 First verify that the receiver is capable of Real time Z operation On Screen 0 verify that Real time Z 1s shown in the middle of the seventh line and that the firmware version number in the lower right corner is similar to 1J00 1C63 where the J indicates Real time Z Next enter sub command 888 on Screen 8 to check the options The last letter of the OPT line must be a J Finally verify that the receiver is in rover mode by selecting PHASE DIF on Screen 4 and using to select ROVER mode at the upper left of the Carrier Phase Mode Selection screen Press e View Screen 20 by pressing 0 then 4 Base doesn t show Screen 5 CPD Data Link Status page Verify that the receiver is in base mode by selecting PHASE DIF on Screen 4 and using to select BASE mode at the upper left of the Carrier Phase Mode Selection subscreen Press e Go to Screen 5 by pressing 5 then select the CPD data link status page by pressing 4 twice Base CPD Data Link Status page doesn t show PRN numbers Verify that the antenna connection on the back of the receiver is connected to the GPS antenna The GPS antenna must be mounted outdoors with a cle
21. PD Fast CPD off achieves the ultimate in GPS accuracy With Fast CPD off sub centimeter position solution accuracy can be obtained with fixed integer ambiguities However it suffers from solu tion delay This delay is caused by measurement and radio link delays The measurement delay is about 1 second Typical radio data link delays are about 1 second also DLf and Tf are not shown on Screen 20 when Fast CPD is off Turning Fast CPD on reduces the solution delay to less than a quarter second Because Fast CPD projects the solution ahead in time it does not suffer from radio link delays However the position accuracy is only 2 3 centimeters Turning FAST CPD on also allows the solution to be available when there is a temporary data drop out from the base station Base Position If the transmitted base position were entered incorrectly at the base you may change this field at the rover to USE ENTERED BASE POS and then enter the correct base coordinates in the OTHER COORDINATES subscreen The CPD data link status on Screen 5 will display the RCVD CORD age as 999 SEC when the entered page position is used If you are using the transmitted coordinates which is the recommended method you can verify the transmitted position by viewing the OTHER COORDINATES subscreen Ambiguity Fix Mode In the Advanced Solution Parameters subscreen the ambiguity fix mode can be set from 1 to 5 The default setting of 4 is recommended for most static and k
22. PUT CPD POS FULL INITIALIZE ENTER RAW BASE POS FAST CPD ON UPDATE RATE 1 SEC c to cancel to change e to enter NO WEST SOUTH MENU NORTH EAST YES Figure 29 Screen 4 Solution Parameters Selection Subscreen Dynamics Select the dynamics for the fastest speed that you expect to be moving If the dynamics are not set properly the CPD solution will be less accurate Use the STATIC dynamics mode only if the antenna will remain on a solid setup such as a tripod If the antenna is on a pole that may have some slight movement select Q STATIC If you are doing stop and go kinematic or rapid static surveys the WALKING or AUTOMOBILE dynamic should be selected SHIP dynamics assume limited vertical movement AIRCRAFT dynamics assume higher speeds and accelerations Multipath Set this parameter to the expected GPS signal multipath environment according to the list below SEVERE Forest urban canyon HIGH Water surface nearby buildings MEDIUM Cropland occasional tree or building LOW Flat terrain no nearby objects NONE No multipath Initialization If you wish to reset the carrier phase cycle ambiguities that have been found select FULL INI TIALIZE The message PHASE DIF SOLUTION IS INITIALIZED will be displayed Note that 39 Real time Z Supplement your position accuracy will temporarily degrade and you should wait until the ambiguities are fixed again before expecting centimeter accuracy Fast C
23. RIER PHASE MODE SELECTION subscreen 5 Press e to accept the CPD mode setting A message will be displayed to indicate the output port and baud rate for the DBEN message Press any key to clear this message 6 Change to Screen 5 and use 4 to select the CPD Data Link monitoring page Verify that at least five PRNs are shown RVP Base Setup 1 Connecting the data radio to Port 2 via a RS 232 data cable turn on the receiver and the data radio 2 Change to Screen 4 and select PHASE DIF to view the CARRIER PHASE MODE SELECTION subscreen Press three times to select RVP BASE mode 3 If you know the coordinates where the RVP base station is located perform the follow ing commands 45 Real time Z Supplement Select THIS COORDINATES and press 1 Enter the WGS 84 latitude longitude and altitude using the degrees minutes seconds format Mea sure and enter the slant distance and antenna radius Press e to accept the coordinates and antenna offset parameters This will bring you back to CARRIER PHASE MODE SELECTION subscreen 4 If you do not know the base station coordinates perform the following commands While in the CARRIER PHASE MODE SELECTION subscreen select SOLUTION PARAMS and press 1 Move the cursor to ENTER RAW BASE POS Press e to use the current position computed by raw pseudo ranges for the base coordinates A confirmation message will be displayed Press c to clear this message Press c again t
24. Real time Z Supplement Supplement to Z 12 Receiver Operating Manual Covering Real Time Z Functions Real time Z Supplement Supplement to Z 12 Receiver Operating Manual Ashtech Document Number 600292 Revision C Publication Date September 1996 Copyright 1995 1996 Ashtech Inc All rights reserved No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or oth erwise without the prior written permission of Ashtech Inc Further this publication and features described herein are subject to change without notice For further information on translations and distribution outside the U S A please contact Ash tech Inc NO PATENT LIABILITY IS ASSUMED WITH RESPECT TO THE USE OF INFORMATION CONTAINED HEREIN WHILE EVERY PRECAUTION HAS BEEN TAKEN IN THE PREPA RATION OF THIS PUBLICATION ASHTECH ASSUMES NO RESPONSIBILITY FOR ERRORS OR OMISSIONS NOR IS ANY LIABILITY ASSUMED FOR DAMAGES RESULT ING FROM THE USE OF THE INFORMATION CONTAINED HEREIN Trademarks used herein are the property of the respective companies Printed in the United States of America Ashtech Inc 1170 Kifer Road Sunnyvale CA 94086 Customer Support 1 800 229 2400 U S only Voice 408 524 1600 FAX 408 524 1500 BBS 408 524 1527 Real time Z Supplement FCC USER S MANUAL STATEMENT Class A Verification Requirements This equipment has been
25. SOUTH lt MENU gt NORTH EAST YES Figure 23 Screen 20 Page 2 26 Real time Z Supplement Screen 20 rege 3 WGS84 01370 0 0240 M PNE 0 0177 M 0 0124 M 0 0211 M s 0 0166 M s GMT 00 35 IT 01 RUN 000 NO WEST SOUTH MENU NORTH EAST YES sae Figure 24 Screen 20 Page 3 Screen Screen 20 Page 4 WGS84 013 2689135 9811 M 4303964 4868 M 3850320 3681 M 0 0138 M S 0 0203 M S NO WEST SOUTH lt HENU gt NORTH EAST YES EE IEEE Figure 25 Screen 20 Page 4 27 Real time Z Supplement Screen 20 Page 5 WGS84 01370 GMT 00 35 44 0 0026 M t 01 RUN 000 0 0050 M 0 0203 M 0 0041 M s 0 0110 M S 0 0370 M S NO WEST SOUTH MENU NORTH EAST YES Figure 26 Screen 20 Page 5 The left side of each page displays the position velocity and a solution quality value The right side of each page displays the solution status and other information Position Information The left side of the five pages displays the rover s position coordinates in WGS 84 local ENU East North Up frame relative to the base station s position Earth Centered Earth Fixed ECEF XYZ the vector solution between the base and rover stations in X Y Z and vector solution in Distance Azimuth and Elevation Position information on page 1 of Screen 20 can be displayed in various datums or in UTM coordinates An important
26. The RVP rover s position will be stored into the receiver s memory if the RVP CPD solution is available for that epoch Otherwise the base station s raw pseudo range position will be stored for that epoch After downloading the recorded data using GPPS HOSE or PRISM TRANSFER program from the RVP base receiver the RVP rover s position and velocity will be stored in the B file See the GPPS or PRISM manuals for a description of the B file format 46 Real time Z Supplement APPENDIX A DATA RADIO DEFAULT PARAMETERS To program the data radio default parameters connect one end of the supplied I O cable to the COMI or COM2 port of a personal computer PC Connect the other end to to the data radio Run the CONFIG96 data radio setup program to configure the following default parameters Owner Ashtech Channel Select i0 DTE DCE Baud Rate 9600 RF Link Baud Rate 9600 Mode Transparent w EOT Time Out EOT 10 Retries 0 FEC Enabled Scrambling Enabled Address local 0 Address Dest 255 Digi squelch Low sensitivity 95 dBm DTE DCE Parity None Break to Pack Disabled Tx ACK Timeout 1 08 The channel RF link baud rate and digi squelch can also be set via the Z 12 receiver MODEM subscreen 47 Real time Z Supplement 48 Real time Z Supplement Symbols PASO O I EE E Da en me EE e 36 SPASIIS CPDUDYIBU 2 sos eee aude d e e c tv EE S EIE 36 SPAS ES CPDIEST sangeet aeta d e o a te et 36 SPLAS
27. V data processing RCVD CORD displays the age of the received base station coordinates in seconds RX DT average interval of incoming CPD differential messages QA displays the percentage of DBEN messages received over the last three minutes A typical radio link has a QA value between 90 and 100 percent AGE displays the DBEN message age in milliseconds This is always zero at the base 34 Real time Z Supplement CPD SOLUTION STORAGE AND UTILIZATION To maintain compatibility with existing Z 12 interface software the existing real time solution output format and data storage have not been changed in Real time Z However when operating the receiver in CPD rover mode or RVP base mode the messages and stored data will contain the precise CPD solutions In addition some new real time output messages have been added to sup ply additional CPD solution information Solution Storage If your receiver has the external memory option you can store the raw measurements and the solution information into the receiver s memory These data can then be downloaded to a PC into B E and S file format via Ashtech s GPPS HOSE or PRISM TRANSFER programs at a later time The receiver s data storage control is the same as a standard Z 12 Simply verify the following receiver setup parameters In Screen 4 the INTVL MIN SV and ELV MASK control the satellite measurement data storage and output The ELV MASK setting on the base affects which satellite
28. a from the rover station and computes the rover s position REAL TIME Z SYSTEM OVERVIEW This chapter describes the hardware configuration for the Real time Z system The system is divided into a base station and a rover station In the discussion throughout this supplement the terms rover and remote are commonly interchanged These terms both refer to the station at which the position is to be determined Base Station Configuration Figure 1 shows the configuration of a typical base station GPS Antenna P N 7007 18 Z 12 P N 700845 Base Radio Amplifier P N 103853 Radio Cable P N 730004 1 O Data Cable P N 700617 Radio Antenna Cable Z 12 Battery Cable P N 103858 P N 700423 ba dak To external processing computer Battery Cable P N 103852 Base Radio Antenna User supplied MI P N 103710 RS Power Battery 12 v 8AH H 8860A P N 103754 Figure 1 Typical Real Time Z Base Station Ashtech part numbers are shown for all the major components Check your equipment to verify Real time Z Supplement that you have all these items The low power Z 12 receiver the key component of the Real time Z base system requires a power source capable of providing 10 32 volts DC at 1 5 amps The power source shown in Figure 1 is a standard 12 volt 8 amp hour Ashtech battery Caution Since the battery life is limited to about 8 hours of operatio
29. al time Z Rover Station stas 4 Typical RTCM RTK Configuration oee ee 7 UCP ED sa orca EED Ae SE EEE 10 DETO rare stee Dee ed Ed ee dele ae Oe ek 11 Screen 4 Subcommands Subsereen et e ye ek RR e ue 11 Screen 4 Configuration Identification Display 12 Screen 9 Site and Session Control nnana naana lees 13 Screen 4 Modem Setup Menu coiere kee EDD RU b EC Reed 14 Screen 4 Modem Setup Subscreen aaa eeen eee nee 15 Screen 4 Carrier Phase Mode Selection vee 16 Screen 4 This Station Coordinates Subscreen 000000000 17 Screen 4 Subcommands Menu 18 Screen 4 Modem Setup Ment v 2ewlasc exert DER ba st 19 Screen 4 Modem Setup Subscreen 0 0 2 cece cee eee eee 20 Screen 4 Carrier Phase Mode Selection Subcreen 21 Screen 4 Receiver Controla atasca a eee es 22 Screen 4 Subcommands Subscreen 0 0 0 0 cece eee eee 23 LIL OAN Pase AAA E e EREA a a a le 24 A a VL 24 Eeen A Paed torsen A E ae 25 Sereen 20 Page T tas A ee Rd 26 Screen 20 Page aio e Sut auia Parti st d 26 Screen 20 Page 9 42 0 644 ya ese i EGG VEN ao a sv v CORE SEG rx 21 Sereen 20 AA A E RECEN 27 Doreen 20 Pafe Sune es dat ee a anitae a a ed 28 Screen 5 Page 3 Phase ResidualS Leia Xa ERE 31 Screen 5 Page 3 CPD Data Link Status for Base 33 Screen 4 Solution Parameters Selection Subscreen 39 Carrier Phase Initialization 325 4 ed aie baa c e dda tie e Rt s 41 Screen 4 Messages Transmitting R
30. ance and antenna radius Press e to enter the coordinates 6 If you do not know the base station coordinates select SOLUTION PARAMS and press 1 Move the cursor to ENTER RAW BASE POS and press e A confirmation message will be displayed Press c to clear this message Press c again to exit the solution parameters subscreen k Press e to store the CPD mode settings A message will be displayed to indicate the out put port for the DBEN message Press c to clear this message The base station coordinates will now be displayed at the top of the screen Caution Do not power on the data radio before connecting the UHF antenna Permanent damage may result 8 Turn the base data radio on The red power lamp will be continuously illuminated and the green status lamp will blink once each second as a set of DBEN messages are transmitted on your licensed radio frequency Your Real time Z base station is now operational Rover Station Setup DBEN 1 Set up the GPS antenna with an unobstructed view of the sky Connect the GPS antenna to the Real time Z receiver Connect the UHF antenna to the data radio Connect the data radio s serial port to Port 2 of the Real time Z receiver Connect the power cables to the Real time Z receiver and data radio 2 Turn on the Real time Z receiver If the receiver settings have been changed from the fac tory default settings you may restore the default settings by pressing down the 4 key while swi
31. ar view of the sky Nearby buildings and vegetation can block the GPS signals or introduce multipath by reflecting the GPS signals Base beeps and Screen 4 position flashes The entered coordinates differ from the computed coordinates by more than 500 meters Verify and re enter the coordinates on Screen 4 or use the SOLUTION PARAMS subscreen to enter the raw position as the base coordinates Base data radio status light isn t blinking every second Verify that the port setting on the Screen 4 PHASE DIF subscreen matches the serial port that the data radio is connected to Remember that Port A corresponds to Port 1 on the back of the receiver and Port B corresponds to Port 2 Set the baud rate to 9600 on the Screen 4 PORT A or B subscreen Verify that the NMEA REAL TIME and VTS outputs are off Verify that RTCM mode is disabled Check that the DBEN message interval is set to 1 second on the DATA SELEC TION subscreen of Carrier Phase Mode selection Verify that on the MODEM subscreen of Screen 4 the port and modem type are set for the Ashtech radio Turn off the radio press 1 and then any key Turn on the radio and verify that you get a TEST PASSED message Press e to re program the data radio Run the data radio setup software per Appendix A and per the data radio manual to verify that the radios contain the default settings Rover data radio status light isn t blinking every second Verify that the PHASE DIF and MODEM serial port settin
32. ata storage memory press at the PUSH ANY KEY prompt in step 4 and the receiver will display a message asking you to press 12 Real time Z Supplement YES within 10 seconds to reset the external RAM the data storage memory WARNING Resetting the data storage memory will erase all previously stored data files Press YES This display is shown below Testing external RAM board RAM option board test passed Push any key to continue When the prompt for PUSH ANY KEY TO CONTINUE is displayed again which could be a minute or two if you have a large amount of data storage memory press any key to complete the reset procedure Resetting the receiver returns all parameters to their factory default values and erases any stored almanac information The first time after this reset the receiver will take slightly longer to acquire satellites Set Up the Base Station Assuming that the base station has not been previously set up and all its parameters are at their factory defaults perform the following steps Enter Site ID A meaningful site identification name aids in data management and post processing A site ID must be entered at the base for surveying l Go to Screen 9 by pressing 9 Screen 9 Site and Session Control SITE 222 SESS _ ROVE CANTA MMDD OP CODE CHICO DRYCWET RH BPO MIN SV O BEF 0 0000 00 00 00 O000 RECORD Y AFT 0 0000 00 00 00 0000 EPOCHS 000
33. ation in each message it sends both GPS carrier phase and pseudo range measurements Sensitivity The Z 12 receiver MODEM subscreen is used to change the sensitivity of the radio from low to medium or high depending on the area and the amount of interference For the base station the recommended sensitivity setting is low while for the rover station it is medium or high If you select a channel and you notice that the radio status light is blinking there is probably someone broadcasting on that frequency and you should select different channel if you have another available While both the base and rover radio s have been preset to operate in a typical Real time Z system some applications may require changes to the radio parameters Appendix A tells how to change the radio parameters and what the default parameters are Further information can be found in the included radio manual 42 Real time Z Supplement ERROR SOURCES OF CARRIER PHASE DIFFERENTIAL GPS Error sources affecting the performance a real time CPD GPS system can be separated into two groups those that affect the radio data link and those that affect the Z 12 GPS receivers Radio Link Dropout When the rover does not receive the DBEN messages it will continue to compute its CPD posi tion for about thirty seconds if Fast CPD is on However the three dimensional position error sigma will increase during this period When the DBEN messages are re acquired the sigma
34. attery 12 v P N 103754 Figure 2 Typical Real time Z Rover Station Ashtech part numbers are shown for all the major components in this figure Check your equip ment to verify that you have all these items The low power Z 12 receiver is the key component of the Real time Z rover system It requires a power source capable of providing 10 32 volts DC at 1 5 amps A rover radio is used to receive the GPS measurements transmitted from the base station One of the Z 12 receiver s RS 232 serial ports is connected to the rover radio to receive the DBEN mes sages from the radio The rover radio requires 10 15 volts at 0 1 amps Figure 1 shows a standard Ashtech 12 volt 8 amp hour battery powering both the Z 12 receiver and rover radio QUICK START GUIDE This chapter shows you how to get your Real time Z system operating within a few minutes The chapter is divided into two sections The first section guides you through differential setup using Ashtech s proprietary DBEN message The second section guides you through differential setup using the new RTCM RTK Type 18 19 messages Base Station Setup DBEN l Set up and level the GPS antenna tripod over a known point with an unobstructed view of the sky Connect the GPS antenna to the Real time Z receiver Connect the UHF antenna to the data radio Connect the data radio s serial port to Port 2 of the Real time Z receiver Connect the power cables to the Real time Z receiver and data radio Rea
35. ayed turn off the data radio and repeat steps 4 through 6 Turn the radio on only when the message SETTING INTERFACE TO RADIO MODEM is dis 19 Real time Z Supplement played Screen 4 Modem Setup Subscreen NO WEST SOUTH MENU NORTH EAST YES EE Figure 15 Screen 4 Modem Setup Subscreen You can change three items on this screen the channel the data link speed and the sensitivity When the cursor is at the V field you can select the CHANNEL between 00 and 15 by pressing the or key When the cursor is in the 2 character field to the right of V you can type in the channel ID 0 15 Also you should use the or keys to select the SENSITIVITY and LINK SPEED Make sure you are using the correct frequency that you have a license for and that your data link speed is 9600 baud Also verify that the sensitivity is set to MEDIUM or HIGH Press e to program the data radio Caution Do not unplug the serial cable or power down the data radio dur ing programming The radio memory will be corrupted and will require reprogramming the default parameters See Appendix A for instructions on reprogramming the default parameters Press e to exit to Screen 4 20 Real time Z Supplement Set the GPS Receiver in CPD Rover Mode 9 Move the cursor to the PHASE DIF field Press e to display the Carrier Phase Mode Selection subscreen Screen 4 Carrier Phase Mode Selection Subcreen
36. creen 0 when Fast CPD is off This is also the delay of the real time output messages when Fast CPD is off 29 Real time Z Supplement To stop the update of information on any of the five pages of Screen 20 a freeze mode is avail able If c is pressed when Screen 20 is active information on the screen is not updated This is useful for those who need to record information directly from the Screen 20 display To switch this mode off press c again 30 Real time Z Supplement Screen 5 Page 3 of screen 5 shows information on CPD phase residuals and status This screen is relevant for a CPD rover or for a reverse vector base RAP Screen 5 Page 3 Phase Residuals gt iud CPD PHASE RESIDUALS ND AND STATUS PRN 03 17 21 23 28 01 31 AMBFIX STS ELY 49 25 68 39 28 65 33 X 1 00 EFF 00 01 00 00 O2 00 00 RESD SIGMA EFP 00 00 01 00 00 01 00 f 1 6 25 4 t2P 01 00 00 00 00 00 01 amp 0 8 22 2 Press a v toggle pages ala il o NO WEST SOUTH lt MENU gt NORTH EAST YES ooo IE ICC Figure 27 Screen 5 Page 3 Phase Residuals CPD Phase Residuals The left and center portions of the screen display information regarding the individual phase residuals associated with each space vehicle SV This information is divided into the following five PRN The PRN pseudo random number field shows the PRN numbers of all the satellites be
37. d dani dap baat ee Cerere uide 42 tibrach adaptadas 9 Typ ESL sts tet ate cb al tas tales oe a duo Sa i eld Sur uot ene 4 8 U UB Moat pee LEADS Ed AL DU es UM MAC EE P Aaa tel 36 A Rr 3 ULP Antena onere ed etes iet hh re tecta ts t etie A re te t d celat eri ERE 5 unhealthy Sate ite antenne neat utto s uec aec Sallie cec diu 35 o A te etae edet a a a En iem 28 V VECTOR SODUDOL NA oN Dena d adel Se eque ted Vales I i e quee 36 VSCOM A sedis teure IN AN etta dass uo A am ou orae 35 Vehicle MA VIO AION aoa toda etd ee cence Sande Woedende auk emu Seals Jaa hada MEO UTE ME 1 version UPDDGE ll lt ltda 10 MTS senden dt ee ande nt hs ele NS ee deeb ads 36 W WOSSSdA attende ae eda A IS 5 17 46 X b do YA es ES cS Uo CIDE Dee PNE A PRSE TOPICS PSU DENT MA 28 53
38. e name must be entered at the base station as well Other Ashtech Real time Z products with software running on a handheld datalogger automate this process but it may be performed in the basic Real time Z system using the following proce dure Check the solution in Screen 20 to ensure that the current accuracy meets your requirements Place the antenna over the point to be measured then issue the following serial commands to the 35 Real time Z Supplement receiver using Ashtech s REMOTE program or a similar serial port I O program PASHS CPD DYN 0 PASHS CPD FST OFF PASHS SIT xxxx where xxxx is the site name you wish to use These three commands set rover motion dynamics to static turn Fast CPD off and set a site name To improve the vector solution you may wait for 5 10 epochs of data before issuing the next set of commands PASHS CPD DYN 2 PASHS CPD FST ON PASHS SIT 222 These three commands reset the unit for dynamic operation The receiver will beep twice indicat ing that the vector solution has been created Now enter the next command to log the solution to the OBEN file PASHQ OBN After this you can move the GPS antenna to the next site Real time Solution Output The CPD rover position velocity and other solution information can be output via the receiver s serial port in PBEN message format or NMEA message format The output control of these mes sages is the same as the standard Z 12 operation The PBE
39. e this delay may be acceptable for some applications such as static point sur veying it may not be acceptable for certain vehicle navigation and kinematic surveying applica tions To reduce the position solution latency a Fast CPD algorithm has been implemented in the receiver It utilizes the differential correction scheme which is commonly used in the pseudo range differential GPS as well as an optimized data processing scheme to reduce the CPD solu Real time Z Supplement tion delay to less than a quarter second Vector Processing and Reverse Vector Processing The most commonly used real time differential GPS operation is to place one receiver at a known position to serve as the base station The base station transmits its raw measurement data over a radio link Multiple rover stations receive the raw measurement data from the base station and compute their positions more accurately using this data This operational mode is widely used in vehicle navigation and in land and aerial surveying However the Real time Z system is not constrained to operate in this mode alone For applica tions such as robot monitoring and remote machine control you may want to know the rover s position at the base station This is called Reverse Vector Processing RVP When the Real time Z system is configured in RVP mode the raw measurement data from the rover station 1s trans mitted The base station which is placed at a known site receives the dat
40. eceiving Subscreen 44 Real time Z Supplement INTRODUCTION Principles of Carrier Phase Differential GPS The fundamental concept for any differential GPS system is to utilize the GPS measurement data from a stationary GPS receiver at a known site base station to correct the errors in the measure ment data of a GPS receiver at an unknown site remote station The GPS measurement data transferred from the base station to the rover station can be either pseudo range measurements carrier phase measurements or a combination of both They can be in either raw data format or in a specific correction format For real time differential GPS operation this data is transferred via a radio link The most common real time differential GPS system uses a standard pseudo range correction for mat called RTCM The pseudo range differential GPS can achieve from several meters down to a sub meter level of accuracy To achieve accuracy down to centimeter level the carrier phase data must be used as well A differential GPS system which uses the pseudo range and carrier phase measurement data is called Carrier Phase Differential CPD GPS Ashtech s Real time Z system operates in CPD mode The pseudo range and carrier phase mea surement data are transmitted from the base station to the rover station in a differential message These messages can be one of two kinds DBEN or RTCM RTK This allows the rover station to com The Real time Z system ut
41. ellites T o Se z a 2 S 9 tc Seconds User selectable settings for speed and reliability from 1 fastest through 4 most reliable are indicated above Results based on 12 000 tests over 0 1 2 4 7 and 9 km baselines 9185 Figure 30 Carrier Phase Initialization Update Rate If you wish to slow down the rover s solution update rate you can change the Update Rate from 1 to 5 seconds This does not affect the Screen 20 update rate which is always 1 second when fast CPD is on When you set the Update Rate to 2 or more seconds the Sigma displayed on Screen 20 each second will increase between computations DBEN Message Interval The DBEN message interval at the base can be set from 0 no DBEN messages sent to 999 sec onds This is useful if your application does not have a continuous data link or only requires peri odic DBEN messages Setting the rover s update rate to match the DBEN message interval allows the rover to compute solutions at the DBEN message rate The FULL P CODE and UNSMOOTHED selections on the DBEN DATA Format Selection page are for display only and indicate L1 and L2 P code and unsmoothed pseudo ranges are being used Base Station Elevation Mask In the base station set the ELEV MASK to 5 degrees to output GPS measurements for all tracked satellites You can set a higher elevation mask angle for position computation in the POSITION subscreen of the rover 41 Real time Z Supplement Radio Para
42. gs are correct Check that the PORT baud rate is 9600 Verify that the NMEA REAL TIME and VTS outputs are off Verify that RTCM mode is disabled Check the radio setup on the base and rover to verify that the same chan nel and frequency are being used Verify that a line of sight path exists between the base and rover data radio antennas Place the base station data radio in high power mode Run the data radio 37 Real time Z Supplement setup software per Appendix A and per the data radio manual to verify that the radios contain the default settings Base station status on Screen 5 is not 00000 At the base station enter antenna height and base coordinates Verify that the entered base coordi nates are correct Verify that Screen 0 shows LK for STAT PL1 and PL2 for at least four satel lites Position is not updating on rover Screen 20 Verify on Screen 5 page 3 that at least 4 PRN numbers are shown in normal video A reverse video PRN number indicates that not all signals are being tracked for that satellite Reposition the GPS antenna away from obstructions On Screen 20 verify that the SVs ROVR and SVs BASE rows show at least 4 SVs are being tracked for P1 and P2 Verify that the number of satellites common between the base and rover is 4 or more This number is shown in the last column of the SVs ROVR row on Screen 20 Screen 20 doesn t update every second or beeps and flashes OLD Monitor the data link quality on Screen 5 T
43. gs by pressing U while switching the receiver on Continue pressing U until the internal test message appears Release U and press the YES 8 key After Real time Z Supplement the internal test completes press any key to continue the power on sequence 3 The Skysearch screen Screen 0 will be displayed when the Z 12 comes on Wait until four channels display LK which indicates that the GPS satellite signal has been locked on This should take less than a minute View the position screen by pressing 2 Because the almanac information is erased during the internal test up to four minutes may be required before the first position is displayed If at any time the display backlighting turns off press any key to turn it back on 4 Press 4 to view the Mode Control screen Press e and move the blinking cursor to the upper left field Enter the known coordinates of the antenna If the antenna coordinates are not known enter the current autonomous position as a reference position Select SOLUTION PARAMS and press 1 Move the cursor to ENTER RAW BASE POS and press e A confirmation message will be displayed Press c to clear this message Press c again to exit the Solution Parameters screen 5 Press 4 to view the Mode Control screen Press e and move the cursor to DIFERNTL Press e again to view the Differential Mode Selection subscreen Press to change the mode from DISABLED to BASE Use the right arrow key to highligh
44. he QA number should be 90 or higher Verify that FAST CPD ON is selected on the Solution Parameters subscreen of PHASE DIF Verify that a line of sight path exists between the base and rover data radio antennas Place the base station data radio in high power mode Refer to the System Performance Optimization Chapter Screen 20 only shows float solution On Screen 20 verify that the SVs ROVR and SVs BASE rows show at least 5 SVs are being tracked for P1 and P2 Verify that the number of satellites common between the base and rover is 5 or more Even if 5 or more satellites are tracked you still may not get a fixed solution at loca tions with severe multipath Real time Z solutions are not being stored in the rover Verify that on Screen 8 RAM BOARD NOT INSTALLED is not shown Verify that OUTPUT CPD POS is selected in the Solution Parameters Selection subscreen of Carrier Phase Mode Selection Verify that Screen 9 RECORD is set to Y Verify on Screen 8 that several EQHR are available Set the INTVL on Screen 4 to 1 second for a faster recording rate 38 Real time Z Supplement SYSTEM PERFORMANCE OPTIMIZATION CPD Solution Parameters The Solution Parameters Selection subscreen of the Carrier Phase Mode screen allows you to match the CPD solution parameters to your specific application These parameters unless other wise indicated are set at the rover only Screen 4 Solution Parameters Selection Subscreen USE XMITED BAS POS OUT
45. ignal has been locked on This should take less than a minute View the position screen by pressing 2 Because the almanac information is erased during the internal test it may take up to four minutes before the first posi tion is displayed If at any time the display s backlighting turns off press any key to turn it back on 4 Press 4 to view the mode control screen Press e and move the cursor to DIFFERNTL using the arrow keys Press e again to view the DIFFERENTIAL MODE SELECTION subscreen Press twice to change the mode from DISABLED to REMOTE Press e to store the setting Press e again and move the cursor to PHASE DIF Press e again and press twice to select rover Press e to store the setting The rover is now programmed for RTCM RTK CPD mode 5 Turn the data radio on The red power lamp will be continuously illuminated and the green status lamp will blink each second as a set of DBEN messages are received on your licensed radio frequency Your Real time Z rover station is now operational 6 Press 2 to view the position screen Press _ to view the CPD rover position page This page now displays the rover s position with centimeter accuracy Your Real time Z system is now operational Note The RTCM auto differential mode will be automatically activated once your Z 12 has been configured as a roving unit This enables the Z 12 to continue to compute a position autono mous in the event that a disruption occu
46. ilizes Ashtech s PNAV data processing engine It processes the raw measurement data from both base receiver and the rover in double difference form Double differ ence processing is widely used in post processing geodetic surveying software It can achieve the ultimate differential GPS accuracy centimeter to millimeter level On the Fly Ambiguity Resolution The most important feature of the Real time Z system is its ability to resolve the cycle integer ambiguities of the carrier phase measurements while the rover station 1s moving thus the term on the fly is used With a PDOP less than two and five or more common satellites in view of the base and rover stations the Real time Z system can achieve centimeter level accuracy very quickly typically in less than a minute Fast Carrier Phase Differential Another important feature of the Real time Z system is the Fast CPD algorithm which reduces the position solution latency or delay Whether it is pseudo range or carrier phase differential GPS the most accurate solution is obtained by processing the matched time tag data from both the base station and the rover station This is not a problem in post processing since all of the raw data is recorded in the files For real time applications using the carrier phase differential CPD technique the position solution could be delayed up to 2 seconds This is due to the extra data processing required and the latency of the radio data link Whil
47. ill be continuously illuminated and the green status lamp will blink once each second as a set of RTCM RTK messages are transmitted on your licensed radio frequency Your Real time Z base station is now operational Note The Z 12 provides the user with two different formats for RTCM RTK Type 18 19 mes sages Format A is the default setting and is recommended for Ashtech to Ashtech operation For Ashtech to Trimble operation use Format B Format B can be engaged through screen 8 by enter ing the command 731 To swich back to Format A enter the command 730 or perform an internal memory reset Rover Station Setup RTCM RTK 1 Set up the GPS antenna with an unobstructed view of the sky Connect the GPS antenna to the Real time Z receiver Connect the UHF antenna to the data radio Connect the data radio serial port to Port 2 of the receiver Connect the power cables to the Real time Z receiver and data radio 2 Turn on the receiver If the receiver settings have been changed from the factory default set tings you may restore the default settings by pressing down the key while switching the receiver on Hold down the key until the internal test message appears Release _ and press the yes key 8 After internal test completes press any key to continue power on sequence 3 The Skysearch screen Screen 0 will be displayed after turning the unit on Wait until four or more channels display LK which indicates that the GPS satellite s
48. indicator of position solution quality is the SIGMA parameter The SIGMA value is an estimation of the 3 D position error based upon an RMS computation PNAV Solution Status PNAV status parameters on the right side of Screen 20 can be used for information about the cur rent state of the PNAV processing engine The top line shows a time indication This time is for the currently displayed position solution which is delayed from the time shown in Screen 0 The amount of delay or latency depends on the data link and whether Fast CPD is on or off See the section System Performance Optimization for more information on Fast CPD PN INIT and RUN Parameters INIT and RUN display how many initializations and runs of PNAV have occurred PN FLAGS OK UP NO X The four parameters OK UP NO X show the internal state of PNAV 28 Real time Z Supplement States of PNAV It can have the following states OK working normally FT full initialization BR bad residual ME missed epoch 2 Solution type It can have the following states UP updated PR projected 3 Cycle slip It can have the following states NO no cycle slip CS cycle slip 4 Ambiguity fixing status flag X integer ambiguities are fixed F integer ambiguities are float not fixed SVs ROVR and SVs BASE These parameters allow you to see how many satellites the receiver is tracking the PL1
49. inematic surveying applications Setting the mode to 5 results in the highest reliability that the ambiguities are fixed correctly but also results in a longer time to resolve the ambiguities and give the fixed solution Setting the mode to 2 or 3 decreases the time to resolve the ambiguities and give the fixed solution but also increases the chances that the ambiguities are fixed incorrectly Setting the mode to 1 results in the shortest time to resolve the ambiguities however mode 1 also has the highest chance typi cally 2 4 percent that the ambiguities are fixed incorrectly The illustration on the next page shows test results for over 12 000 ambibuity fix tests done by Ashtech at various baseline lengths up to 9 km These test results indicate that at the default set ting mode 4 the typical time to resolve the ambiguities is 60 seconds with a reliability of 99 9 percent At the fastest setting mode 1 the results indicate that the typical time to resolve ambi guities is 5 seconds with a reliability of 96 6 percent If the ambiguities are fixed incorrectly the satellite geometry must change appreciably before the ambiguities will again fix correctly For a static rover this will happen within approximately 10 minutes or when a new satellite is acquired 40 Real time Z Supplement Carrier Phase Initialization 8 Satellites 4 468 eo 100 0 p 2 3 4 99 8 3 99 8 Average 5 8 Satellites 5 Sat
50. information is contained in the DBEN message Also set RNGR to 0 to collect all raw measurements or 2 to only store the position information In the POSITION subscreen UNHEALTHY should be set to N so that unhealthy satellite signals are not used to compute the position The base will transmit DBEN message information for unhealthy satellites but the rover will use them only if this flag is set to Y in the rover In Screen 9 set the SITE name and set RECORD to Y Since CPD is a differential operation a solution may not be available if the differential data link is lost However the receiver will always store the raw measurements whether the CPD solution is available or not When the CPD solution is not available the position computed by the raw pseudo ranges will be stored instead Vector Solution Storage This capability allows you to log vector solutions containing the same information as post pro cessed vector output files allowing the measurements to be imported into an adjustment program Your Real time Z measurements may then be included as part of a least squares network adjust ment To use this option a valid site name must be entered in Screen 9 and the rover s GPS antenna must remain stationary until the site name has been changed to If the GPS antenna is mov ing with a site name entered the vector solution will not be valid If no site name is entered the vector solution will not be created Note that a sit
51. ing the default parameters Press e to exit to Screen 4 15 Real time Z Supplement Set Up the GPS Receiver in CPD Base Mode 11 From the Screen 4 list of subscreens move the cursor to PHASE DIF and press e The following map shows the options available under PHASE DIF PHASE DIF Option En CARRIER PHASE MODE SELECTION Subscreen Press 1 tor options EE A ao RACE gt Disabled POSITION USF PORT DATA SELECTION SOLUTION PARAMS THIS COORDINATES OTHER COORDINATES ADVANCED Base Press SelecL Press 1 ress 1 Press 1 Press 1 Press 1 cL AME for options pors A for options for options for options for options for options RVP Rover POSITION FIX DBEN DATA SOLUTION THIS STATION OTHER STATION ADVANCED PARAMETERS FORMAT PARAMETERS COORDINATES COORDINATES SOLUTION Subscreen SELECTION SELECTION Subscreen Subscreen PARAMETERS Subscreen Subscreen Subscreen POS Mode Latitude Latitude PDOP Mask Interval Walkin Slant Slant Ambiguity Fix Unhealthy Full P Code Use XMIT Longitude Longitude ALT Mode Unsmoothed Medium Multipath Radius Radius HDOP Mask Full Initialize Altitude Altitude Ton Model Fast CPD V Dist V Dist ELV Mask Qutput CPD AZM AZM VDOP Mask Enter Raw H Dist H Dist Pos Comp Update Rate XMIT INTVL Fix UTM Fix Zone UTM Coord Screen 4 Carrier Phase Mode PH Menu A POSITION USE PORT B DATA SELECTION SOLUTION PARAMS THIS COORDINATES ADVANCED PARAMS OTHER COORDINATES fe to change e to enter c to cancel
52. ing used in the rover or RVP base solution computation The PRN field is a listing of all SV s common to both base and rover which are being used in the solution computation ELV The ELV elevation field provides the current elevations of all common SV s LIF The LIF field contains phase residual measurements for each SV in terms of the Fast CPD cycle Accordingly the L1F field will not contain any information if the Fast CPD cycle is not engaged Reverse video indicates a negative phase residual for that SV All measurements are reported in millimeters L1P L2P The L1P and L2P fields contain phase residual measurements for each SV in terms of the regular CPD cycle Once carrier phase operation is initiated either DBN or RTCM RTK these fields will begin displaying phase residual information for both bands Reverse video indicates a nega tive phase residual for that SV All measurements are reported in millimeters 31 Real time Z Supplement The right side of the screen displays information associated with the ambiguity fixing status and RMS error values This information is divided into the following three fields AMBFIX STS Information relating to the ambiguity search is presented in this field The far left side of this field will contain either an X or an F An X signifies a fixed CPD solution where the ambiguities have been resolved An F signifies a float CPD solution where the ambiguities have not been resolved The far
53. l time Z Supplement 2 Turn on the Real time Z receiver If the receiver settings have been changed from the fac tory default settings you may restore the default settings by pressing down 4 while switching the receiver on Hold down 4 until the internal test message appears Release 4 and press the YES key 8 After the internal test com pletes press any key to continue the power on sequence 3 The Skysearch screen Screen 0 will be displayed after turning the unit on Wait until four or more channels display LK which indicates that the GPS satellite signal has been locked on This should take less than a minute View the position screen by pressing 2 Because the almanac information is erased during the internal test it may take up to four minutes before the first position is displayed If at any time the display s backlighting turns off press any key to turn it back on 4 Press 4 to view the mode control screen Press e and move the blinking cursor to PHASE DIF using the arrow keys Press e again to view the Carrier Phase Mode Selection subscreen Press to change the mode from DISABLED to BASE 5 If you know the WGS 84 coordinates where the base station is located select THIS COORDINATES and press 1 Enter the latitude longitude and altitude using the degrees minutes seconds format If the coordinates are known in degrees minutes format enter them on the first line of Screen 4 Measure and enter the slant dist
54. left side of this field will contain either 1 00 or a number less than 1 00 A display of 1 00 indicates a fixed CPD solution whereas a number less than 1 00 indicates the ambiguities have not been resolved RESD The RESD residual field contains the root mean square RMS phase residual errors for the fast CPD cycle and for the regular CPD cycle The RESD field is divided into the sub fields f and c The f sub field contains the RMS phase residual errror in millimeters for the LIF field The c sub filed contains the RMS phase residual error in millimeters for the combined L1P and L2P fields SIGMA The SIGMA field contains the 3 D RMS position estimation error for the fast CPD cycle and for the regular CPD cycle The field opposite the f displays the 3 D RMS position estimation error in millimeters for the fast CPD cycle The field opposite the c field displays the 3 D RMS position estimation error in millimeters for the regular CPD cycle DATA LINK MONITOR Screen 5 is used to monitor the status of the data link being used for CPD Pages 1 and 2 of Screen 5 show RTCM and satellite range error information Press twice to view page 3 which dis plays the CPD data link status for either the base or rover stations This page is activated only when receiver is in CPD mode Base Screen 5 32 Real time Z Supplement When the receiver is in CPD BASE mode page 3 of Screen 5 looks like Screen 5 Page 3 CPD Data Link Status for Base
55. ll accompany this flashing for one minute Warning The following setup is valid only for distances less than 1 Km More accurate base station coordinates are required for any other situation If you do not know your coordinates you can log the currently computed position First make sure your GPS receiver is computing position by viewing Screen 2 and seeing that the position is continuously being updated with PDOP less than 5 From Screen 4 move the cursor to the PHASE DIF field Press e Move the cursor to the SOLUTION PARAMS field Press 1 Move the cur sor to the ENTER RAW BASE POS field Press e The message RAW POSITION IS ENTERED AS BASE POSITION will be displayed Press c to clear the message Press c once more to return to the Carrier Phase Mode Selection subscreen Press e to exit to Screen 4 17 Real time Z Supplement Save the Setup 15 From Screen 4 move the cursor to SUBCMDS and press e Screen 4 Subcommands Menu e to enter c to cancel NO WEST SOUTH MENU NORTH EAST YES ooo Figure 13 Screen 4 Subcommands Menu 16 Enter 555 and press e This will save the parameters for the base station so that the setup will not need to be performed again after the receiver has been turned off or a loss of power has occurred 17 Press e to return to Screen 4 The setup is complete Set Up the Rover Station Assuming the rover receiver has not previously been set up
56. lled separately You may want to install the radio antenna on a high mast for long distance transmission 4 Connect the GPS antenna to the Z 12 receiver with the 10 meter GPS antenna cable 5 Connect the radio antenna to the base radio transmitter with the radio antenna cable Refer to the radio manual for connections for high or low output 6 Connect the appropriate data cable between base radio and the Z 12 receiver Note For consistency it is recommended that you use Port 2 on the back of the Z 12 receiver This is because Port 2 will also be used on the rover s Z 12 receiver for connection to its radio T If you are using an Ashtech supplied 12 volt battery connect this to the Z 12 receiver using the power cable If you are using your own power supply make sure it can deliver at least 12 watts of power a minimum of 10 volts at 1 5 amps Turn the Z 12 receiver power switch on Warning Never power on a radio without first connecting an antenna to it 8 With the above warning in mind connect power to the radio transmitter using the radio power cable and turn the power on Rover Station Set up the rover station as specified in the following procedure 1 Place the rover GPS and radio antennas on their mounts 2 Connect the GPS antenna to the Z 12 receiver with the 10 meter GPS antenna cable or the 3 meter GPS antenna cable Real time Z Supplement 3 Connect the rover radio antenna to the radio using the cable from the
57. meters Careful consideration must be given to the following situations to get the full performance from the radio data link Line of Sight Transmission The Real time Z system uses radios operating in the VHF UHF frequency range These frequen cies are predominantly line of sight The base station antenna should be placed as high as possible for maximum range However this needs to be balanced with reasonably short radio antenna cables due to the relatively high transmission line loss on a cable when using VHF UHF frequen cies Foliage buildings or desert terrain may shorten the transmission distance while improve ment may be found in transmissions over water snow or ice The following is a formula for computing the approximate line of sight distances that can be achieved between the base and rover stations d sqrt 3 K h 2 where dis the line of sight distance in miles h is the base station antenna height in feet K is the surface reflectance coefficient which is 1 33 for temperate climates polar climates will have larger K values Data Transmission Rate To provide real time accurate rover position solutions at a 1 second rate the Real time Z system requires radios which can transmit data at a speed of at least 4800 baud For best performance radios capable of a 9600 baud data link speed are strongly recommended A high data link speed is required since the base station has to transmit a large amount of data to the rover st
58. n it is recommended that you use another power source for longer base station operation The Z 12 receiver tracks the GPS satellites by using an antenna which is mounted in a location with good visibility to the whole sky This antenna is of high quality designed to lessen the effect of multipath errors Caution Make sure to mount the GPS antenna away from any large obstructions Also do not mount the GPS antenna near any metal objects since these objects will reflect the GPS satellite signals causing multipath errors Mounting the antenna higher will usually reduce the multipath effect A base radio is used to transmit the GPS measurements from the base station to the rover station One of the Z 12 receiver s RS 232 serial ports is connected to the base radio to transfer its mea surement data to the radio for transmission Note that the base radio is also powered by this cable via the Z 12 receiver s power supply The base radio draws 0 8 amps at 10 15 volts and provides 2 watts of RF output However the supplied base station radio also has a 35 watt amplifier which allows data to be transmitted over longer distances This amplifier must be powered by a source capable of delivering 10 15 volts at 10 amps Caution It is recommended that you use a heavy duty power source such as a car battery for longer base station operation Caution It is NOT recommended that you power the Z 12 and base radio amplifier with the same power source
59. o exit the solu tion parameters subscreen Press e to accept the CPD mode setting This will bring you back to CARRIER PHASE MODE SELECTION subscreen 5 Press e to accept the CPD mode setting 6 Change to Screen 5 and use 4 to select the CPD Data Link monitoring page Verify that at least five PRNs are shown and that the QA number is increasing toward 100 Solution Monitoring Switch to Screen 20 on the RVP base to view the position and velocity of the RVP rover with cen timeter accuracy The Fast CPD calculation time Tf is replaced by the message RVP BASE Fast CPD is automat ically turned off in RVP mode because the base can not predict the movement of the rover Solution Output and Data Storage The real time PBEN CBEN and NMEA messages at the RVP base station will now contain the position and velocity information for the RVP rover These messages will be available only if the RVP CPD solution is available By default the RVP base receiver will not store the RVP rover position into the receiver memory In order to store the rover position into the receiver memory perform the following Change to Screen 4 and select PHASE DIF to enter the CARRIER PHASE MODE SELECTION subscreen Select SOLUTION PARAMS and press 1 Move the cursor to OUTPUT CPD POS Select the OUTPUT RVP POS by pressing or Press e to accept the change and exit the solution parameters subscreen Press e to accept the CPD mode setting
60. operational RTCM RTK Carrier Phase Differential CPD Setup Overview The Real Time Z 12 receiver provides the ability to generate or receive RTCM RTK Type 18 19 messages This feature makes the Z 12 ideal for navigation and machine control precise survey ing and extremely accurate positioning Using the new RTCM RTK Type 18 19 message format the Z 12 produces the ultimate in real time precision sub centimeter position accuracy under ideal conditions Coupled with the quick measurement option the Z 12 can output RTCM RTK solutions at 1 Hz 2Hz and even 5 Hz All of these high speed position updates are new indepen dent solutions with extremely low solution latency typically 100 to 125 milliseconds Additionally the Z 12 can even take advantage of RTCM compliant messages from receivers manufactured by other companies e g the Trimble 4000ssi This design provides the versa tility and performance necessary to complete any job requiring precision solutions Base Station Setup RTCM RTK 1 Set up and level the GPS antenna tripod over a known point with an unobstructed view of the sky Connect the GPS antenna to the Z 12 receiver Connect the UHF antenna to the data radio Connect the data radio serial port to Port 2 of the Z 12 receiver Connect the power cables to the Z 12 and the data radio 2 Turn on the Z 12 If the receiver settings have been changed from the factory default settings you may restore the default settin
61. pseudo range PL1 carrier phase and PL2 carrier phase measurements and using in the DBEN messages of the rover and base receiver If there is no DBEN message at all a will appear here The number of common satellites between the base and rover stations is shown at the end of SVs ROVR row Additionally at the end of SVs BASE row there is a flag that can have two states and When the DBEN message is received by the serial port of the receiver this flag is set to when the DBEN message is not being received this flag is set to DLf and Tf DLf shows the delay from GPS time to the starting time of Fast CPD position computation in milliseconds Tf shows the computation time of the Fast CPD solution in milliseconds The quantity DLf Tf shows the total delay of the Fast CPD solution This number should be the difference between the times displayed in Screen 20 and Screen 0 This is also the delay of the real time output messages When Fast CPD is turned off this line displays DLf 00000 fCPD OFF DLc and Tc DLc shows the delay from GPS time to the starting time of the matched time tag position com putation in milliseconds Tc shows the computation time of the matched time tag PNAV pro cessing solution in milliseconds The quantity DLc Tc shows the total delay of the matched time tag solution This number should be the difference between the times displayed in Screen 20 and S
62. roadcasts its raw measurement data via a data radio The base station which is at a known site receives the rover s raw measurement data and applies phase corrections to it in order to compute the rover s CPD position Reverse vector processing can be used to track autonomous vehicles or control remote vehicles in three dimen sions with centimeter accuracy Equipment Setup Equipment setup is similar to that of a normal CPD setup except that the large high power data radio is used at the rover to transmit and the smaller low power data radio receiver is used at the base to receive RVP Rover Setup 1 Connecting the data radio to port 2 via a RS 232 data cable turn on the receiver and the data radio WARNING Do not turn on the radio power if there is no antenna connected to the radio amplifier 2 If you are using the Ashtech data radio you might want to verify the data radio parame ters or change the channel as described in the normal CPD setup 3 Change to Screen 4 and select PHASE DIF to view the CARRIER PHASE MODE SELECTION subscreen Select RVP ROVER mode by pressing four times 4 If you are interested in getting a position other than that of the antenna phase center perform the following Select THIS COORDINATES and press 1 Enter the antenna offset parameters slant radius vertical offset horizon tal distance and azimuth Press e to accept the antenna offset parame ters This will bring you back to the CAR
63. rs If the receiver displays the message CANNOT CONNECT TO RADIO MODEM check your cable connections and radio power source Also check the PORT field on the Modem Setup subscreen and the baud rate in the Port A or B Setup subscreen If the message BAD CHECKSUM WAS RECEIVED is dis played turn off the data radio and repeat steps 4 through 6 Turn the radio on only when the message SETTING INTERFACE TO RADIO MODEM is dis 14 9 10 Real time Z Supplement played Screen d Modem Setup Subscreen NO WEST SOUTH lt MENU gt NORTH EAST YES Bossa E TES Figure 10 Screen 4 Modem Setup Subscreen You can change three items on this screen the channel the data link speed and the sensitivity When the cursor is at the V field you can select the CHANNEL between 00 and 15 by pressing the or key When the cursor is in the 2 character field to the right of V you can type in the channel ID 0 15 Also you should use the or keys to select the SENSITIVITY and LINK SPEED Make sure the channel is set to transmit on the frequency that you have a license for and that your data link speed is 9600 baud Also verify that the sensitivity is Press e to program the data radio Caution Do not unplug the serial cable or power down the data radio dur ing programming The radio memory will be corrupted and will require reprogramming the default parameters See Appendix A for instructions on reprogramm
64. rs to the differential data link EQUIPMENT SETUP This chapter describes in detail how to set up both the base and rover stations for Real time Z sys Real time Z Supplement tem operation Refer to Figures 1 and 2 in the Real time Z System Overview chapter which show the physical connections between all the necessary equipment for the base and rover Note that radios have already been pre configured to operate as required by the Real time Z system Spe cific directions for configuring and operating the base and rover radios are given in the chapter System Performance Optimization Base Station Below is a step by step procedure for setting up the base station 1 Select the site for the base station GPS antenna Where feasible the base station GPS antenna should be mounted for an unobstructed view of the sky For permanent installations the antenna should be mounted on a mast 2 3 meters high to reduce multipath Do not mount the antenna over water or metal surfaces Nearby foli age such as trees can also introduce multipath 2 Install the base GPS antenna over a monument that is a known location This is typically done by using a tripod tribrach and a tribrach adapter Measure the antenna height above the monument 3 Install the base radio antenna Note that the radio antenna can be installed at the GPS antenna location by placing the included mounting bracket between the GPS antenna and the tribrach adapter or it can be insta
65. sce caelos ade te alae poe toca cota a Leg 40 remote riac he control ooo oot deca hala tet ot kcu a iuuat beue do 2 St DE 32 reverse VECLOL DSE uude atiende dias 31 TOVELSO VECLOR IOC CSS ITE ds ros b bi miii passu dada ern Erud eens kens 2 TOGO MOTO LD E een mh dd 2 TOVER POSI Unt Read Nga da 46 lA renee unten tee a oa 3 45 RICM inenen NE ee AE 37 RTEM RTK A AA NN d eA 1 4 lar a 2 45 S BUY eenen alice Sn Motum ende RM dE 43 satellite DeORIetIy eei etm etui veter Po VEA UON Gate ptg n me ast dattts ao 40 suene MONTE 22 SOSA en ae eee eend 20 42 SHE ID on D CRI m 13 SUA M EM m emu LL qu 35 Slant distance conem dU Mutina mu MN a al ROM te 46 s l tion delay oi o petu id tras stas nene ad 40 solution ALE CY se Maeve error C be ir be d bl voir Re teab 6 21 solution tpdate Tate iii di dila Duel aa Gc inb 41 Static PONCE SVT tadas 1 stat s A O 8 store CED mode SS oe vaa e ada 5 Store CPD r yer mode Setting on oon ate pa en tetro ecu tee e UU e aute ce e nde dec aa 6 T A en ee iN outline c ostrea T 29 TEST MESSAGE euo eati ehe c a ut oM a S ea Dale e d 5 6 TE e 29 AME NAE AAA P G M 1 TIME LA POSITION Ad 29 IM prin ADOS A e erp oda ea um cond tested 6 52 Real time Z Supplement DRAIN SEE Re nd ce ene Veille C e ede ded EE ccn rs 35 transmission ine lOS S o n a oa E obs EE Td I
66. so in page 3 can be displayed in various datums or UTM coordinates by selecting the appropriate parameters in Screen 4 Screen 2 Page 2 GMT 00 15 36 HE 01 PALO ALT NO WEST SOUTH lt MENU gt NORTH EAST YES o00000 0 0 0 a Figure 20 Screen 2 Page 2 Screen 2 now has an additional page page 3 accessed by 4 or w when the receiver is set to 24 Real time Z Supplement ROVER mode for CPD Screen 2 s Page 3 3 RV 02550 GMI 0 26 0000 M ented 330 50 Tr SOG 0 50 Km h d WEST SOUTH MENU NORTH EAST T YES Figure 21 Screen 2 Page 3 Notice that the layout of page 3 is identical to page 1 except that there is more precision in the LAT LON ALT parameters and the SGM parameter is shown instead of FOM The SGM param eter or sigma is the root mean square RMS three dimensional position error for the current epoch 25 Real time Z Supplement Screen 20 Screen 20 of the rover receiver is accessed as follows Press 0 to go to Screen 0 then press 4 to go to Screen 20 There are five pages in Screen 20 which display the CPD solution in different formats andina 20 Dy Page 1 LON121 59 50 36557U E 14 8130 M 0 0073 M S 0 0132 M S 0 0229 M S NO WEST SOUTH MENU NORTH EAST YES Figure 22 Screen 20 Page 1 Screen 20 Page 2 01370 WGS84 20 2731 M 337 06 47 04453 01 07 10 31117 0 0000 Tr 0 0179 M S NO WEST
67. t the RTCM format field Press 1 to access the RTCM setup screen Set the following parameters RTCM MODE to BASE SPD to 0000 MESSAGE TYPE 1 to 1 second MESSAGE TYPE 3 to 1 minute MESSAGE TYPE 18 19 to 1 second EOT to CRLF The remaining message types can be set to 0 second See the Z 12 manual for setting the remain ing values for quick start leave at the default values A typical RTCM RTK base setup will be configured as follows Typical RTCM RTK Configuration ia Li RTCM MODE BASE STID 0000 STHE 0 a SPD 0000 MAX AGE 0060 SEQ N QAFREQ 100 TYPE 1 2 3 16 18 19 6 EOT Y FREQ OF DO OF DO 01 OFF CRLF 4 rj MESSAGE c e to change e to enter c to cancel NO WEST SOUTH lt MENU gt NORTH EAST YES 0 1 2 5 JE ES Es Lz sJ Figure 3 Typical RTCM RTK Configuration 6 Press e to store the RTCM RTK mode settings A message will be displayed to indicate the output port for the RTCM RTK message Press c to clear this message The base station coordi nates will now be displayed at the top of the screen Real time Z Supplement CAUTION DO NOT POWER ON THE DATA RADIO BEFORE CONNECTING THE UHF ANTENNA PERMANENT DAMAGE MAY RESULT 7 Turn the base data radio on The red power lamp w
68. tching the receiver on Hold down the 4 key until the inter nal test message appears Release a and press the YES key 8 After the inter Real time Z Supplement nal test completes press any key to continue the power on sequence 8 The Skysearch screen Screen 0 will be displayed after turning the unit on Wait until four or more channels display LK which indicates that the GPS satellite signal has been locked on This should take less than a minute View the position screen by pressing 2 Because the almanac information is erased during the internal test it may take up to four minutes before the first position is displayed If at any time the display s backlighting turns off press any key to turn it back on 4 Press 4 to view the mode control screen Press e and move the cursor to PHASE DIF using the arrow keys Press e again to view the Carrier Phase mode selection subscreen Press twice to change the mode from DISABLED to ROVER 5 Press e to store the CPD rover mode setting 6 Turn the data radio on The red power lamp will be continuously illuminated and the green status lamp will blink each second as a set of DBEN messages are received on your licensed radio frequency Your Real time Z rover station is now opera tional T Press 2 to view the position screen Press 4 to view the CPD rover position page This page now displays the rover s position with centimeter accuracy Your Real time Z system is now
69. tested and found to comply with the limits of Class A digital device pur suant to Part 15 of the FCC rules These limits are designed to provide a reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful inter ference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures Reorient or relocate the receiving antenna Increase the separation between the equipment and receiver Connect the equipment into an outlet on a circuit different from that to which the receiver is connected Consult the dealer or an experienced radio TV technician for help Shielded cables and I O cords must be used for this equipment to comply with the relevant FCC regulations Changes or modifications not expressly approved in writing by Ashtech may void the user s authority to operate this equipment INDUSTRY CANADA STATEMENT This device complies with RSS 210 of Industry Canada Operation is subject to the following two conditions 1 this device may not cause interference and
70. tetval itasse a Het p d aqu qud ec atone 41 Base Station Elevation Mask esiti dec enten ios 41 Radio AR ALIN CUCU Sarns ens oaeen eeens 42 Line of Sight Transmission ae A RA tee e aea Res eed deae qa 42 Data Transmission Rate e oe ed D RE beat De sy sansa 42 SOM UTR IA nett A a O RE 42 ERROR SOURCES OF CARRIER PHASE DIFFERENTIAL GPS 43 Radio Link Dropout nannieb ada 43 GPS Signal A A mU aee E MATE NE 43 Sat llite GEO tb cocum ee E cea las e 43 Maintaining Lock to the Satellites ns snee venen etende benenden 43 Selective Xvallabllitys sieve feed D aedi te ro Perque oed leet defe emu dee Pie 43 MESSAGE CONTROL T ep es ttes bata Hi a esu pepe M e pis Mae UR sen Mods 44 REVERSE VECTOR PROCESSING iii di 45 Equipment SUP A 45 RV PROVEE SU io 45 BO VP Base CUS O E due 45 Solution MODIDODIBE rsss ausartena nage eapite lssatida 46 Solution Output and Data Storage uns aanv ene ersnereneeenseerseersneeenneenseersveeenveenn 46 APPENDIX A DATA RADIO DEFAULT PARAMETERS 47 Real time Z Supplement LIST OF FIGURES Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 Figure 31 Typical Real Time Z Base Station eenen eeen 2 Typical Re
71. the receivers tracking 8 satellites with a PDOP of 2 or less Maintaining Lock to the Satellites During the operation of the Real time Z system it is recommended that continuous lock to the GPS satellites be maintained for best performance Having uninterrupted data from the satellites provides faster ambiguity resolution and better position accuracy since more data can be used Therefore make sure to place the GPS antennas for both the base and remote stations so that they have a good view of the whole sky Do not mount them near any large obstructions How ever since it is understood that tracking satellites continuously is sometimes not possible due to obstructions such as bridges and trees the Real time Z system can still recover from these situa tions and provide the best accuracy possible Selective Availability Selective Availability SA is the intentional degradation of the GPS satellite signal by the US Department of Defense Like multipath SA is strongly correlated but unlike multipath it affects the base and rover stations about the same way Therefore most of the SA effects can be removed by a differential GPS system Note that small position errors will still be present due to SA for any real time differential GPS system This is because the rover may have to predict the SA effect for the time gap caused by the radio link delay 43 Real time Z Supplement MESSAGE CONTROL The Message subscreen allows you to exchange
72. up DBEN rd aladas eter au eee e toa attenderen dead 5 RTCM RTK Carrier Phase Differential CPD Setup sse 6 EQUIPMENT SETUP x eternet etn ie quads tele dea heath dene dinde cu Ud gut ipu did 8 Biase Stan stock cite IRI else lp S Ui boe M fedus alu e Ple M deze rx d 9 Rover Sali isti deae iini Sao aay neee een blanket inkeer ael qune iau 9 RECEIVER CONFIGURATION A O aes 10 Gheckahg Options tio eu as oen Dc ot tre atn ide en oit 10 Res t the A LN 12 Set Up the Base Stations me ns teh te i e pe esa ec on E ce 13 Enter Site ID onmens ial raden dend 13 Set Up the Radin T 14 Enter the Base Station Coordinates u s ten rita land sdiapaesaceabeaditedwansdaasisbesdiets 16 Save the SEP aee eoe etse neee disse hA eden ait eta Re sene eb aue 18 SEU Rover A des aso a e o do 18 SR a t e ala 18 Set the GPS Receiver in CPD Rover Mode essere 21 High Speed Solution Computation smse mert iaa 21 Save the Setup Parameters ssi i seo exei pitt tn po sede a ERR E P e ee e 22 ROVER SOLUTION MONITOR inenen beerse 23 A a a E AY 23 Sat da NC E E M uu 26 Position Informatio nn it Et 28 PNA V Solution Status in i e oec aari nne nee esate aaa 28 A E EE E E M E 31 CPD Phase Residuals xut els eed tela n M E 31 DATA LINK MONITOR iie den EA ANS 32 A r A 32 Rover Screen diameter a an 33 CPD SOLUTION STORAGE AND UTILIZATION eene 35 Solution Stor gen eie eerie A eee 35 Vector Solution SOLA BE AA 35 Real time Solution
73. will immediately drop to the value before the radio link drop out If Fast CPD is off CPD position computation will stop within seconds of losing the DBEN messages For best results in the field Fast CPD should be left on and the base radio antenna should be located as high as possible with a line of site to the rover GPS Signal Multipath Multipath is by far the most unpredictable error source affecting differential GPS position accu racy Multipath is also one of the largest error sources and because it has strong correlation it requires a longer time to average out its affect While most error sources can be canceled out by a differential GPS system multipath can not because it is a local effect That is multipath affects the base station and rover station differently To avoid large multipath effects do not place the GPS antenna near any metal objects vegetation or water since the GPS satellite signals reflect off these objects very easily and corrupt the reception of the direct signals from the satellites Also try to mount the antenna higher to reduce the effect of ground multipath reflections Satellite Geometry The recommended satellite geometry is to have the Z 12 GPS receivers both base and rover track at least 5 common satellites above the elevation mask angle with the PDOP Position Dilu tion of Precision less than 4 Of course the more satellites the receivers track the better The best performance can be obtained with

Z12 RTK Supplement

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