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SeaShark Detailed Design Document

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1. Table 5 17 Format of the Image Extent structure Page 51 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 Latitude Latitude of the segment point 90 90 in degrees 1000000 Longitude Longitude of the segment point 0 360 in degrees 1000000 Image_row Image row of the segment point ane Stop Size in Short Description sere ue Type i 1 i 1 1 1 Image_col Image column of the segment point Table 5 18 Format of the Coastline Point structure 5 4 5 Calibration Data File AVHRR Only The calibration data file holds the sensor code in a header record whose format is shown in Table 5 19 Name Short Description Sensor_Co Three character sensor code de Table 5 19 Format of the Calibration Data Header record The file also holds slope and intercept values for converting the raw image values to radiance for each of the 3 thermal bands Slope and intercept values are calculated for every line of image data and are stored in the calibration data file as a series of records whose format is shown in Table 5 20 ogee Size in Short Description Type Times bytes Copy of the scan line flag from Binary 1 the product s image unsigned short Day of year of the line unsigned 1 short Millisec Millisecond since midnight of unsigned 1 onds the line int BB_Temp Average black body tempera int 1 ture derived from the 4 PRTs
2. Table 7 2 Classes Used by SeaShark Page 100 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 Class Name Description ResourceManager3Key a resource manager which uses three keys to differentiate between resources Key 1 directory name key 2 sub directory name Key 3 file name Used internally by ResourceManager ResourceManager4Key a resource manager which uses four keys to differentiate between resources Key 1 directory name key 2 3 sub directory name Key 4 file name Used internally by ResourceManager ResourceManager5Key a resource manager which uses five keys to differentiate between resources Key 1 directory name key 2 3 4 sub directory name Key 5 file name Used internally by ResourceManager RetrieveCallbacks_c RetrieveBatchQueue class encapsulating callback functions for the Retrieve Window RetrieveDialog_c RetrieveImmediateQueue RetrieveQueue ReverseTransformCoefficients handles the retrieve batch queue handles the retrieve immediate queue used internally by TransformCoefficients provides a recursive move facility RRemove SatelliteOrbitData purely virtual top level class which represents satellite orbit data in all it s different forms eg two line elemnt tbus etc ScanLineBuffer represents a scan line of image data ScanLineField represent a scan line of image data SeaAtmosCorrection PML atmospheric co
3. Any text following the 7 characters contain the comment Note that comments can also appear at the end of configuration lines 9 y a configuration line contains name value pairs separated by an character The name contains the identifier of the configuration parameter to the left of the equals symbol and the value is everything to the right of the equals symbol up to the terminating semicolon A configuration line can be any length and is terminated by a semicolon character the value can in fact be a list containing several values each of which is separated by white space characters the order of the lines is not important but there are some relationships between different lines which must be preserved for example when the numbers of values in one line must equal the number of values in another line Such relationships are described in the file by means of comments Page 66 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 The following extract from a configuration file illustrates these points comment the numbers of the NOAA satellites supported by the software noaa_satellite_numbers 9 10 11 12 another comment noaa9_channel4_start_wavelength 555 43 A complete list of all configurable parameters is given by the Software ser Manual 10 5 10 Log File Format The log file is the means by which a program indicates to SeaShark whether its processing has been succes
4. Table 2 4 C Coding Recommendations Page 10 SeaShark Detailed Design Document GENERAL DESCRIPTION SHK DDD 001 Issue 2 0 Port Rec Description Port Rec 1 Avoid the direct use of pre defined data types in declarations Port Rec 2 Do not assume that an int and a long have the same size Port Rec 3 Do not assume that an int is 32 bits long it may be only 16 bits long Port Rec 4 Do not assume that a char is signed or unsigned Port Rec 5 Always set char to unsigned if 8 bit ASCII is used Port Rec 6 Be careful not to make type conversions from a shorter type to a longer one Port Rec 7 Do not assume that pointers and integers have the same size Port Rec 8 Use explicit type conversions for arithmetic using signed and unsigned values Port Rec 9 Do not assume that you know how an instance of a data type is represented in memory Port Rec 10 Do not assume that longs floats doubles or long doubles may begin at arbitrary addresses Port Rec 11 Do not depend on underflow or overflow functioning in any special way Port Rec 12 Do not assume that the operands in an expression are evaluated in a definite order Port Rec 13 Do not assume that you know how the invocation mechanism for a function is implemented Port Rec 14 Do not assume that an object is initialized in any special order in constructors Port Rec 15 Do not assume that static objects are initialized in any sp
5. The AVHRR HRPT Level 0 file written by the acquisition software can be in one of three dif ferent formats that are acceptable to SeaShark e the DLR type format composed of a 2 Byte header followed by a 16 bit HRPT data block containing a sync in 22180 Bytes followed by a Calibration data block in 346 Bytes total length 22548 Bytes 2 Bytes 22180 Bytes 346 Bytes lt DS eee ee eee eee eee lt lt eee gt H Sync HRPT 16 Bits Calibration Block AE gt 22528 Bytes e the Dundee type format identical to the DLR type but the total record length is blocked to a multiple of 8K memory page size total length 24576 Bytes le ee ee ee ee ey So ES EER A Eee total etch j 24576 Bytes e a basic format without header or calibration data composed of a 12 Bytes sync plus the 16 bit HRPT data in 22180 Bytes total length 22192 Bytes HRPT 16 Bits 22192 Bytes Page 41 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 5 1 2 AQTIM DAT File Format This file is generated during the acquisition and is used to determinate the date of the pass which is not present anywhere in the HRPT and the first and last valid time lines The AQTIM DAT file is a text file The format of the file is described in Table 5 1 par Size in Short Description Format bytes Satellite Number for 3 ASCII NOAA vnn new line char 4 1 acq_start_da
6. 7 6 7 cshre SeaShark Defines the following environment variables SEASHARKHOME SEASHARKDATA SEA SHARKCONFIGFILE SEASHARKTELECOMIN SEASHARKTELECOMOUT QASW_IDL QASW_DATA and DOROEXEC Adds the SEASHARKHOME bin directory to path so that the executables can be found Page 107 SHK DDD 001 Issue 2 0 SeaShark Detailed Design Document Appendix A SOURCE DIRECTORY STRUCTURE AND DESCRIPTION Class interconnection A l In the following section are a selection of diagrams showing the interconnection between class in SeaShark abel dYHS41 Meas 410868111 dYHAaHAd abeu LdHH aapungabewLdyHyHHAY abewlLdyHayHAy Ny WSHN ABEL LdHHHHHAY sda abe JWEysETHHHAY JEDU AM DASUISIO lt abu 8875419885 ABEL SALI BART abel abe 1194974 4HAY 20210 LOJEUS HH HA abe yZdJeySHyHAY abewdJeusHyHAy V V ABELL ATCIEYSHHH abewjuan YSEWESSpPUET abewjayseuns ANA ABEL MEY Figure A 1 Image hierarchy Page A 1 SeaShark Detailed Design Document SHK DDD 001 Issue 2 0 TBUS BrouwerOrbitElements lt TwoLineElement Figure A 2 BrouwerOrbitElement hierarchy CEOSSequenceRecordiD CEOSGenericRecordID CEOS mageRecordID CEOSRecordID Figure A 3 CEOSGenericRecordID hierarchy DistributeQueue RetrieveQueue ArchiveQueue ProcessorQueue QueueHandler Figure A 4 QueueHandler hierarchy l ReverseTransformCoefficients TransformCoefficients a ForwardTransformCoefficients F
7. COMPONENTS SHK DDD 001 Issue 2 0 Class Name Point Description represents the mathematical concept of a point which is used in many places in SeaShark for example in navigation PointCallbacks_c PointWindow_c class encapsulating callback functions for the Point Window PostscriptFilter PressureClimDataLoader functionality associated with the Point Window of the GUI used to generate postscript quicklook files PressureMetDataLoader PressureQueryManager functionality to ingest pressure climate data files into SeaShark functionality to ingest pressure meteorology data files into SeaShark PrimaryWindow ProcessBatchQueue functionality to interrogate the pressure data in the ancillary database functionality to handle lists of tasks in a Window ProcessCallbacks_c ProcessImmediateQueue represents the process batch queue X callback functions for the Process Window of the GUI represents the process immediate queue ProcessingCommand combines UnixCommand and ConfigReader classes to facilitate execution of processing commands ProcessorHandler handles communication with the processor binary ProcessorQueue ProcessWindow_c handler for the processor queue functionality associated with the Process Window of the GUI Product top level level class of all the product that are either generated or accessed within the SeaShark application Product
8. Content of the data Directory on page 23 and See Import on page 72 Page 33 SeaShark Detailed Design Document 3 15 2 Errors PHYSICAL DESIGN SHK DDD 001 Issue 2 0 The following table contain a list of some of the errors that can be generated on attempting to produce an archive product Processing errors are also discussed in the Software User Manual 10 Stage of processing any stage any stage prior to archiving Error text Invalid sensor lt sensor code gt Error cannot open the input cata logue entry file Description or error The sensor used in the product is not listed in station cfg The catalogue iuf has been deleted or made read only archiving Disk full tape index not written for The disk is full lt product id gt importing Failed to read import directory The import directory does not exist or is read only any stage Unable to write Q store file The list of queues is unavailable navigation No valid GPS found please use TLE The GPS does not exist navigation any stage Executable does not exist lt executa The executable mentioned does not ble name gt exist in the SSEASHARKHOME bin directory navigation Product is in an invalid state Import failed import Image read failed the IMAGE_HRPT file does not exist or is read only import Image file is invalid The IMAGE_HRPT file is incor rectly formatted import Not enough memory The disk is full navigation Note enoug
9. Details of the lines and fields in each line are given in Ref 20 and Ref 21 TBUSLine the common parts of all lines of the TBUS Part 4 TBUSLinel the first line of the TBUS Part 4 TBUSLine2 the second line of the TBUS Part 4 TBUSLine3 the third line of the TBUS Part 4 TBUSLine4 the fourth line of the TBUS Part 4 TBUSLine5 the fifth line of the TBUS Part 4 TextCallbacks_c X callback functions for the Text Window of the GUI TextField handles status bars on windows functionality associated with the Text Window of the GUI TimerOptionsCallbacks_c TimerOptionsWindow_c X callback functions for the Tmer Options Window of the GUI functionality associated with the Timer Options Window of the GUI TimeToLine converts a given time to an image scan line number TLE The TLE Two Line Element contains orbital information for SeaStar satel lites It is divided into a number of lines TLELinel the first line of the Two Line Element TLELine2 the second line of the Two Line Element Token used to encapsulate messages to be sent via sockets TransformCoefficients represents the collection of coordinate transformation coefficient which are used to convert between image row and column and latitude and longitude and vice versa in SeaShark navigated products Table 7 2 Classes Used by SeaShark Page 103 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0
10. Short Description Number points in the segment Start byte Stop byte Size in bytes 4 Type Earth_ Extent Segment type DCW defined Range of latitude and longitude values in the segment 1 4 5 8 4 Structure Table 5 16 Image_ Extent Minimum image row of any point in the segment Structure Table 5 17 Structure No_ Points 5 Coastline_ Coordinates of a segment point 41 Varia 16X Point ble No_Points Table 5 18 Table 5 15 Format of the Segment structure ree Start Sto Size in T No Name Short Description p Type Times byte byte bytes 1 Max_lon Maximum longitude of any 9 12 4 int 1 point in the segment 2 Min_lon Minimum longitude of any point in the segment 3 Max_lat Maximum latitude of any point in the segment 4 Minimum latitude of any point in the segment Table 5 16 Format of the Earth Extent structure a All values in the Earth Extent structure are in units of degrees 1000000 Longitude values are in the range 0 360 latitude values are in the range 90 90 ae Start Sto Size in No Name Short Description P Type Times byte byte bytes 1 Max_row Maximum image row of any 25 28 4 int 1 point in the segment 2 Min_row Minimum image row of any point in the segment 3 Max_col Maximum image column of any point in the segment 4 Min_col Minimum image column of any point in the segment
11. ConfigReader a file of configuration information The class provides functions to open a configuration file read an entry in the file parse the entry and convert the entry to a numeric format ConfirmWindow_c class encapsulating callback functions for the Confirm Window functionality associated with the Confirm Window of the GUI converts start stop latitude longitude or time to start stop line number counter which maintains state within a file ConvertToLine Counter CoverageList represents temporal coverage by a series of passes DataLoader base class for climatology and meteorology dataset loaders DCWxxxx DCW xxx classes describe components of the Digital Chart of the World DCW a database of geographical features used for annotation Details of the DCW format can be found in Ref 15 Ref 16 and Ref 17 DCW represents the DCW database DCWBrowse represents the digital chart of the world DCWEdge represents an edge coastline poltical boundary etc within the DCW Ena bles edges to be manipulated DCWFace represents an face within the DCW Enables faces to be manipulated DCWLibrary represents a library wihtin the DCW The DCW is structured as a number of libraries of which 4 are high resolution NOAMER EURNASIA SOAMAFR SASAUS and one is a lowresolution library covering the whole earth DCWName represents a name within the DCW The DCW contains strings which are the name
12. Contains class which provides functional ity for the display canvas Contains various globally used classes for example task queue and import monitor ing globals cc H provides globals struc ture for whole application Contains Kernel files Contains classes which create and main tain tasks and task queues Contains classes providing general win dow utilities Contains classes for each of the window within SeaShark Figure A 11 Interface sub directories Page A 7 SeaShark Detailed Design Document processing_steps Y g alibration O Catalogue_Entry Coastline Orbit_Stitching Postscript _Quicklook SHK DDD 001 Issue 2 0 Contains class used Tor cali bration Contains class to update the catalogue file Contains classes to extract and transform the coastline Contains classes to create a types of distribution product Contains classes to create all types of fdp products Contains classes to import both SeaWiFS and AVHRR Contains classes used to cre ate land sea mask Contains classes to navigate and Interpolate AVHRR data and Navigate SeaWIFS data with gps and tle Contains classes to add and get orbit data Contains classes to detected possible stitchable passes and actually stitch passes together Contains class used to gener ate postscript quicklook Contains classes used to ge
13. Lines 04316 Bad Lines 000 Data Gaps 000 Tilt Value NA Cloud Sa Land Oter o 0 oo es ow oe ox Commer ial Contact Resarch Contact Eurimage ESA ESRIN Customer Services Multi Mission User Service iaG Galitbi CP 64 Via G Galilei CP 64 2 00044 Frascati ITALY 00044 Frascati ITALY Tal 39 6 941902189 Tel 39 6 94190372 Fax 39 5 9426285 Fax 39 6 94 190641 Information ele Te Colour A i Quicklook i la Address Image ve Figure 5 2 Postscript Quicklook File Page 54 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 5 4 8 Catalogue Entry File The format of the Catalogue Entry File is based on the format given by 26 However the cat alogue entry file catalogue iuf distributed as part of the Level 1 Archive Product differs from this format as follows e it contains no header e it contains no trailer e it contains no newline characters The file size is therefore exactly 720 bytes 5 4 9 Acquisition Details File For AVHRR products the acquisition details are stored in the AQTIM DAT file see Section 5 1 2 which is updated so that the start and stop times correspond to the archive image prod uct There is no acquisition details file stored with a SeaWiFS Level 1 Archive Product 5 4 10 Orbit Data File For AVHRR a TBUS file is used The format is described in 35 For SeaWiFS a TLE file is used The format is described in 34 5 4
14. Page 105 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 e 11 Format e 12 Returned Status e 13 Returned Directory Entry e Request Argument is message specific e Number of Products is the number of product ID s to follow e Product ID is the standard product ID The product will be found either on the specified device during read operations or in the archive of the distribute directory during write oper ations 7 5 Programs In this section the internal workings of some of the binaries are briefly described Further information on how to use the binaries including those not mentioned here can be found in 10 7 5 1 Ingest_Climatology Reads raw climatology data in COADS ASCII format or TOMS binary format and proc esses it into SeaShark Auxiliary Database format for use in SeaWiFS level 2 processing Inter polation is used to fill in any holes in the data for the given area of coverage no extrapolation is performed for data points lying outside the area of coverage Interpolation is performed specified via command line argument as follows the average value of the real data points is calculated and assigned to each of the missing data points an iterative process is then applied to each missing data point to smooth the interpolation the value of a missing data point is cal culated as the average of its immediate neighbours providing they themselves are real data points immediate neighbours
15. Table 2 4 C Coding Recommendations Page 9 SeaShark Detailed Design Document GENERAL DESCRIPTION SHK DDD 001 Issue 2 0 Rec Description Rec 32 Friends of a class should be used to provide additional functions that are best kept outside of the class Rec 33 Avoid the use of global objects in constructors and destructors Rec 34 An assignment operator ought to return a const reference to the assigning object Rec 35 Use operator overloading sparingly and in a uniform manner Rec 36 When two operators are opposites such as and it is appropriate to define both Rec 37 Avoid inheritance for parts of relations Rec 38 Give derived classes access to class type member data by declaring protected access functions Rec 39 Do not attempt to create an instance of a class template using a type that does not define the member functions which the class template according to its documentation requires Rec 40 Take care to avoid multiple definition of overloaded functions in conjunction with the instantia tion of a class template Rec 41 Avoid functions with many arguments Rec 42 If a function stores a pointer to an object which is accessed via an argument let the argument have the type pointer Use reference arguments in other cases Rec 43 Use constant references const amp instead of call by value unless using a pre defined data type or a pointer Rec 44 When overloading functions al
16. inate as many warnings as possible Rec 3 An include file should not contain more than one class definition Rec 4 Divide up the definitions of member functions or functions into as many files as possible Rec 5 Place machine dependent code in a special file so that 1t may be easily located when porting code from one machine to another Rec 6 Always give a file a name that is unique in as large a context as possible Rec 7 An include file for a class should have a file name of the form class name extension Use uppercase and lowercase letters in the same way as in the source code Rec 8 Write some descriptive comments before every function Rec 9 Use for comments Rec 10 Use the directive include filename H for user prepared include files Rec 11 Use the directive include lt filename h gt for include files from libraries Rec 12 Every implementation file should declare a local constant string that describes the file so that a UNIX command can be used to obtain information on the file revision Rec 13 Never include other files in an icc file Rec 14 Do not use typenames that differ only by the use of uppercase and lowercase letters Rec 15 Names should not include abbreviations that are not generally accepted Rec 16 A variable with a large scope should have a long name Rec 17 Choose variable names that suggest the usage Rec 18 Write code in a way that makes it easy to change the prefix for global identifiers Rec 19 Enc
17. retention period the time is set in the Clear Order timer A thirty day check is made to examine their Shipping Dates and copy those ESA Orders whose retention period has expired to a backup directory It is the responsibility of the operator to manually remove them from the backup directory if nec Page 37 SeaShark Detailed Design Document PROCESSING INTERFACE SHK DDD 001 Issue 2 0 essary 4 2 5 The Operator Interface The operator interface provides the means for controlling the processing of orders All control takes place using the Task List window as for archive product processing Selecting an order will show the processing steps completed and those still to be performed in the Processing Steps section of the Task List window From here the operator can select which steps are to be performed and execute the processing by selecting the Process button A Confirm window will appear and processing will commence when a queue is selected 4 2 6 Counting The Orders On The System The Main window shows the number of Orders which are on the system either waiting to be processed or undergoing processing Those orders which have been processed and are still on the system pending expiry of their retention period are not included in the total 4 2 7 Viewing The Status Of Orders The Task List window allows the operator to see the details of an Order to initiate its process ing and to monitor its progress It also allows the proc
18. supplies SeaWiFS specific parameters to the FDP text file used internally by SeaWiFSSyncPixels SeaWiFSGainAndTDI represents the field from the SeaWiFS HRPT Image which contains data about the instrument Gain and TDI It it is not currently used but will be required in the future Table 7 2 Classes Used by SeaShark Page 101 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 Class Name Description SeaWiFSGPSOrbitData represents the field from the SeaWiFS HRPT Image which contains orbit information derived from the GPS on the platform SeaWiFSGPSQA holds QA parameters for SeaWiFS GPS and attitude telemetry checks SeaWiFSGPS Values holds GPS values from the SeaWiFS telemetry SeaWiFSHRPTImage provides I O and access to SeaWiFS dependent aspects of SeaWiFS HRPT Images SeaWiFSImportProduct represents the SeaWiES level 0 data as presented to the SeaShark applica tion from the HRPT frame formatter SeaWiFSInstrInfo holds SeaWiFS instrument information for CEOS leader files SeaWiFSInstrTelemetry represents the field from the SeaWiFS HRPT Image which contains data about the instrument state Not currently used but will be required in the future SeaWiFSL1DistProduct represents a SeaWiFS level distribution product SeaWiFSL2Algorithm encapsulates processing algorithms for SeaWiFS L2A L2B and FDP SeaWiFSL2DistProduct represents a Sea
19. Class Name Description TwoDBitMask represents two dimensional bit masks within the SeaShark application TwoLineElement represents orbit information supplied in TLE format UnixCommand represents constructs and executes unix commands from within a program UnixDirectoryList generates list of file and or directories within a given unix directory UnixPath represents unix path names for both files and directories VPFTable represents VPF tables used by the DCW database WindClimDataLoader functionality to ingest windspeed climate data files into SeaShark WindMetDataLoader functionality to ingest windspeed meteorology data files into SeaShark WindspeedQueryManager functionality to interrogate the windspeed data in the ancillary database WorkingWindow_c functionality associated with the Working Window of the GUI ZoomCallbacks_c class encapsulating callback functions for the Zoom Window Table 7 2 Classes Used by SeaShark 7 3 Scripts A list of scripts used in SeaShark For further details see section 7 6 on page 106 Script name Description CleanDataAreas Cleans data directory CreateInstallTape Creates a tar file containing files necessary for a SeaShark installation Cop ies files from the current installation Install Unpacks an installation tape SeaSharkBuildDir SeaSharkBuildComms TidySeaShark Creates SeaShark directory structure Creates SeaShark communication files Removes RCS files object files testfn dir
20. within the file the record is null padded so that its length matches the length of the following Grid_Row records b The length and stop byte are dependent on the number of navigation grid points per line This param eter is defined in the Grid_Dims structure see Table 5 9 c The number of Grid_Row records in the file is defined by the height of the source product s image defined in the Grid_Dims structure see Table 5 9 Page 47 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 Start Stop Size in Name Short Description se price Type Times Grid_Cols Width of the grid 4 unsigned 1 int Calculated_ Number of grid lines within the 5 8 4 unsigned 1 Rows file which were calculated using int the Puccinelli algorithm 14 X_Spacing Gap between grid columns 12 4 unsigned 1 int Y_Spacing Grid spacing between the grid rows that were calculated using the Pucinelli algorithm 16 4 unsigned 1 int Width of the product s image 28 4 unsigned 1 int Height of the product s image 32 4 unsigned 1 int Record_Len Length of the Grid_Row records in the file in bytes 36 4 unsigned 1 int Pad Null padding to give the file a fixed record length Record Record_ unsigned Variable _Len Len 36 int X_Origin Number of first column with a 17 20 4 unsigned 1 grid point Numbered from 0 int Y_Origin Number of first row in the file 21 24 4 un
21. work items might have to wait a short time before they are processed The Process and Batch queues are internally maintained lists of queued Tasks and are initial ised from the Task Pool when SeaShark starts up As queuing information forms part of a Task object there is no danger of the queue states being lost in the event of a system crash for example as all Task files are written to disk If the operator selects several Tasks to add to a queue a multiple selection Tasks will be added as if they had been selected individually and in the order they appear in the Task List window To change the order in which Tasks are processed they must be added to a queue indi vidually in the required order of processing Page 40 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 5 FILE FORMATS This section defines the file formats used within the SeaShark project 5 1 AVHRR HRPT Product The processing of an AVHRR HRPT pass requires the presence of two files after the acquisi tion e the AVHRR HRPT Level 0 file coming from the satellite e the AQTIM DAT file generated by the acquisition software 5 1 1 AVHRR HRPT Level 0 File Formats The AVHRR HRPT Level 0 format has a number of variants The general form of the format is defined in Data Extraction and Calibration of TIROS N NOAA Radiometers Rev 1 Tech nical Memorandum NESS 107 dated October 1988 from NOAA 39 The variants are described below
22. 0 counts before calibration etc Channel 3 will still be treated as an IR channel for AVHRR 2 type instruments 6 13 1 NOAA KLM calibration SeaShark now uses a piece wise function when calibrating channels 1 2 and 3A N ranges for this function can be defined in the sensor configuration file for example channell_calibration_ranges 0 300 600 1024 This defines three ranges 0 299 300 599 and 600 1023 and corresponding to these ranges must be slope and intercept values channell_calibration_slopes 0 12 0 15 0 17 channell_calibration_intercepts 3 0 2 0 1 0 Thus when calibrating channel 1 if a pixel has a count of 100 the slope and intercept values corresponding to the first range would be used namely 0 12 and 3 0 The coefficients for Hol ben calibration are configured in a similar way Ranges are defined but the time dependent coefficients are grouped together A post fixed number on the tag name indicates which range the values belong to For example defined in the NOAA 15 cfg file there would be something like Holben_dates 01 08 1997 01 08 1998 01 08 1999 01 08 2000 Holben_ranges 0 500 1024 Holben values for each of the above dates take the form coefficientl space_offsetl coefficient 2 space_offset2 coefficient3A space_offset3A Holben_values 0 30 38 0 0 42 39 9 0 42 39 9 Values for 01 08 97 030 379 0 43 39 53 0 42 3959 0 30 37 8 0 45 39 1 0 42 39 9 0 30 37 8 0 46 39 0 0 42 39 9
23. 11 ArchiveTape Index File The archive tape index file is created on archiving a levell product See Table 5 21 and Table 5 22 Short A Size in Type Description y Bytes yp Identifies file 52 ASCII ASCII char 012 Table 5 21 Archive Tape index file header record Short Size in hes Type Description y Bytes Identifies Product 16 ASCII The date the level1 10 ASCII product was archived Table 5 22 Archive Tape index file data record Page 55 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 Short Start Size in Description Byte nd bye Bytes Type The time the level1 37 11 ASCII product was archived The size in Mb of 13 ASCII the archive product The offset of the ASCII archive product on the tape new line ASCII char char 012 Table 5 22 Archive Tape index file data record 5 5 Fast Delivery Product The SeaShark Fast Delivery Product FDP consists of two files e a binary image file e a text description file 5 5 1 Image File The image is generated in raw format The image data is stored row wise with one byte per pixel ho header or trailer and no internal compression The file size is as recorded in the description file normally 512 x 512 The image file is transformed to GIF format if this is specified in the order 5 5 2 Description File The description file is a text file containing the information shown in Table 5 23 E Star
24. 2 0 In the IMAGE_RECORD the spare byte at position 24 in PREFIX_DATA is used to indicate which band 3A or 3B is active for a given scan line A value of 0 zero represents 3B and a value of 1 one represents 3A The SUF_DATA field has the slope and intercept fields set to zero for bands 1 2 and 3 when 3A is active 6 13 3 Changes to the LEADER file In the SCENE_HEADER_RECORD position 1413 1800 1413 actual gives the number of active bands normally 5 and for NOAA K processed data where both 3A and 3B data is present this will have the value 6 6 14 SeaWiFS Distribution Products SeaWiFS distribution products generated by SeaShark are similar in form to the AVHRR prod ucts discussed above CEOS LIA The L1A product contains uncalibrated data for all available channels CEOS LIB The L1B product contains calibrated data for all available channels CEOS L2 L2 products contain atmospherically corrected radiances and geophysical products in a configurable combination 43 44 The algorithms used to generate the above products are discussed by the relevant design docu mentation 9 They are based on libraries supplied with NASA s SeaDAS software version 2 0 May 1996 No changes were made to calibration or HDF libraries other than to correct coding errors these are documented in the code itself 6 15 Distribute The files created in the Generate stage of processing are copied onto exabyte tape except for Fas
25. 38 ASCII ity 1 lowest to 9 highest 44 ASCII ddddd0 50 ASCII Shipping dddddO 58 ASCII date New line 59 ASCII char 5 6 8 Order file Table 5 24 Order status file data Record The order file is automatically or manually created in order to create a distribution product Refer to 35 for complete description eon Start Sto Size in No Name Short Description P Type byte Byte Bytes 1 space space 1 1 1 ASCII char 032 ESA Order aaaddddxyy ASCII code where aaa station code dddd counter x order type yy year space ASCII char 032 sub order dddd ASCII number where leading zeros are not printed space space ASCII char 032 6 Satellite id Satellite id 18 18 1 ASCII Table 5 25 Order file data Record Page 59 where dd date mmm month SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 EA Start Sto Size in No Name Short Description P Type byte Byte Bytes 7 Satellite Satellite mission number 20 2 Mission number 8 space 21 1 ASCII char 032 9 Sensor id Sensor id AVHRR or 26 5 ASCII SWIES 10 space space 27 1 ASCII char 1032 11 Product Product code 33 6 ASCII code 12 Latitude cdd mm 39 6 ASCII where c compass direction dd degrees mm minutes 13 space space 40 1 ASCII char 032 14 Longitude cddd mm 47 7 ASCII where c compass direction ddd degrees mm minutes 15 space space 48 1 ASCII char
26. Report Line of the Distribution Report ocoonccnnnnoninnnoccnancninnos 65 Table 5 32 Format of the Report Line of the Media Report cooccnnoccnoccnoccnnncnnnoncnoncnancnnnnos 66 Table 5 33 Archive Tape Format di 68 Table 5 34 Archive Tape Label Borat tic 69 Table 5 35 Archive Tape Directory Format oooooocnnncccnnncccnonnncnnnnncnnncnonnncnonnnononnncccnnnccinnnos 69 Table 5 36 Format of the Archive Tape Directory Entry cooooocnnocccnoncccnoacncnnncnononaconnnacinnnos 70 Table 5 37 Archive Tape Product Files aii dan caes 70 Table 5 38 Distribution Tape Format AA iaa 71 Table 6 1 Distribution product types AVHRR c oooconnoconoconoccnonnnononcnoncnannnonnnnnn cnn ncnnncnnnnno 81 Table 6 2 Distribution product types SeaWI ES eecceesceceseeeceseeeceeceeceeeeecsteeeeeeeeesaes 82 Table 6 3 Extract from the NOAA KLM FILE DESCRIPTOR RECORD 87 Table 7 1 Se astark Processes doi 90 Table 7 2 Classes Used by SeaShark escri rita sacar sadesdsaaasbebaaevarsedaus eins 91 Table 7 3 Seripts used by Seashark iii 104 Table ARE iS 105 page x SeaShark Detailed Design Document List of figures SHK DDD 001 Issue 2 0 List of Figures Figure 3 1 Process Model ui a sondou ea dlessaguaasdenadsvengdeetsadesaaets 12 Figure 3 2 Archive processing CAM Ao 16 Figure 3 3 Distribution processing chain a tios 18 Figure 3 4 Top Level Directory Structure 123 058 tenting eee aes 20 Figure 3 5 Structure of the data Direct
27. Sharp2B from optical product Fast Delivery Product for Normalised Difference Vegetation Index only available from archive products Fast Delivery Product for Sea Surface Temperature only available from archive products Executable used Processes_Sharp1_to_2B Generate_FDP_NDVI Generate_FDP_SST File created VDF NULL_VDF LEADER IMAGE TRAILER LFD1 raw LFD1 txt SFD1 raw SFD1 txt Table 6 1 Distribution product types AVHRR Distribution product Executable used File created LACIA Create_SeaWiFS_LACIA VDF only available from NULL_VDF archive products LEADER IMAGE ANNOTATION LACIB Create_SeaWiFS_LACIB VDF only available from NULL_VDF archive products LEADER IMAGE ANNOTATION LAC 2 Create_SeaWiFS_LAC2 VDF only available from NULL_VDF archive products LEADER IMAGE ANNOTATION Fast Delivery Product for Generate_FDP_CHLA CFD1 raw chlorophyll a CFD1 txt only available from archive products Table 6 2 Distribution product types SeaWiFS Refer to 9 for more information Page 82 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 6 10 AVHRR Distribution Product OverView The SHARP distribution products generated by SeaShark use the calibration algorithms defined in NOAA Technical Memorandum NESS 107 Data Extraction and Calibration of TIROS N NOAA Radiometer 39 SHARP LIB The L1B product contains uncalibrated
28. and Batch Processing SeaShark offers two types of processing Immediate Processing and Batch Processing Imme diate Processing refers to work items which the operator wants the system to execute at the ear liest opportunity Batch processing refers to work items which the operator wishes to make ready for execution but whose execution he wishes to defer until a later time All Processing is carried out by the Processor which sequentially reads items of work from a Process Queue There is only one Processor and only one Process Queue All work items whether immediate or batch are entered into the Process Queue However immediate work items are entered at the top of the queue and are therefore selected for processing first If the Process Queue contains only batch items processing only continues if the operator has turned on the batch processing option This allows the operator to prepare work items which are queued for batch processing which can be turned on at a suitable time typically just before he goes home in the evening Since there is only one Processor which processes one work item from the Process Queue at a time SeaShark has no concept of concurrent processing whereby several work items are being processed at the same time Because of the nature of SeaShark processing there is no signifi cant advantage to be gained by having more than one work item being processed simultane ously by the system This means that even immediate
29. are defined as the eight points surrounding a point in a regular matrix of data points if an immediate neighbour is missing or now has a value gained through interpolation it is not included in the calculation of the average value The number of iterations of the interpolation process can be controlled via a command line argument 7 5 2 Ingest_Meteorology Reads raw meteorology data in ECMWF binary database format or TOMS ASCII format and processes it into SeaShark Auxiliary Database format for use in SeaWiFS level 2 process ing Interpolation is applied in the same manner as described for Ingest_Climatology 7 6 Scripts In this section each script is described 7 6 1 CleanDataAreas Recursively removes files from the data directory Checks that the SEASHARKHOME envi ronment variable is defined and prompts for confirmation before removing files It is assumed that the data directory is located at SEASHARKHOMEY data Files are removed from the fol lowing directories tasks products orders reports telecom in telecom out catalogue and tapes Page 106 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 7 6 2 CreateInstallTape Copies a working version of SeaShark to tape with or without source code Checks that the SEASHARKHOME environment variable is defined and echos this to the shell Prompts the user to determine if source code is required on the tape Rewinds the tape and then uses the UNIX tar comma
30. can only be iconised from the Main Window as Dia logShells lack the functionality to iconise themselves independently Some widgets perform functions when selected e g PushButton widgets and ToggleButton widgets This functionality is accessed through a static callback function the address of which 1s passed as a parameter during widget creation Thus the static function is called every time the widget receives an appropriate event from the X Windows environment Most of the static callback functions are deliberately trivial merely calling a class member function to do the real work This allows the class definitions which control SeaShark function ality to remain encapsulated and separate from the classes which control the interface thereby permitting a certain amount of parallel development Furthermore WorkShop Visual will gen erate C code which creates and initialises all the widgets defined in the graphical widget hierarchy This includes stubs code where the empty callback functions for every window in SeaShark are written to a single file Obviously having all the callback functions for all the windows in the one file could result in an unwieldy and confusing mess so keeping this file simple is vital if the code is to be understood A separate C class exists for every window in SeaShark and each class definition forms a separate module compilation unit Separate classes exist to contain the static callback func tions for each
31. data for all available channels SHARP L2A The L2A product contains equivalent reflectance in channels 1 and 2 radiance in channel 3 and brightness temperature in channels 4 and 5 with non linearity correc tion The method of calibration is discussed below in section 6 11 SHARP L2B The L2B product contains class dependent geophysical parameters in channels 1 and 5 Channels 2 3 4 contain calibrated values as in above L2A product The algorithms used to generate the above products will now be briefly discussed with refer ence to SeaShark specific issues 6 11 Calibration of visible AVHRR channels The AVHRR visible channels have no in flight calibration data and hence rely on pre flight calibration data or for the odd numbered satellites Holben coefficients 6 11 1 Even numbered satellites The effective albedo measured by the sensor for channel 7 is computed as a linear function of the input data value as follows Ci l c A X CNA c B for i 1 2 Where CN J c digital counts band i for pixel of coordinates J c A Slope value for band i B Intercept value for band i Ci c effective albedo band i for pixel of coordinates J c Using effective albedo the equivalent radiance r can be calculated thus r l c d2 x CA c cos O0 1 c where d 1 0 01672 x cos 0 9856 x DayOfYear 4 L c Solar zenith angle for pixel of coordinates c Internally SeaShark optimises this calculation by i
32. identifier for the customer for the order e Media the distribution media type identifier 4 2 8 Initiating Order Processing When an Order first enters the system it is in the retrieve state in which it can be selected and Page 38 SeaShark Detailed Design Document PROCESSING INTERFACE SHK DDD 001 Issue 2 0 initiated Retrieval starts the processing chain The required steps in the chain are determined by SeaShark and the appropriate steps are checked in the Task List window Once the Order has been initiated it proceeds automatically The operator would not normally intervene in the processing unless e operator intervention is needed to place an archive or distribution medium in the tape drive The system uses a pop up dialogue to prompt the operator when medium handling for example the insertion of a tape needs to be done e the operator wishes to cancel the Order This is done from the Task List window in which case the Order reverts to the uninitialised state and can subsequently be reinitialised 4 2 9 Viewing Full Order Details In the Task List window the most important details from the Order are shown Full details can be seen by selecting the Order Form button in the Task List window which will cause the Order Form window to be displayed This shows information as it is appears in the Order itself including the fields which are not needed by SeaShark 4 2 10 Entering New Orders 4 2 10 1 External Orders For externa
33. instrument is the split gains for channels 1 2 and 3A This will in effect increase the sensitivity at low light levels hence improving ice snow and aerosol products These new features can be easily accessed and customised through the appropriate SeaShark sensor con figuration file There have been some slight changes to the level0 HRPT to incorporate the new features intro duced by the AVHRR 3 instrument Most importantly a flag is present in each minor frame word 7 Bit 10 indicating whether the scan line is from the 3A or 3B sensor This enables Sea Shark to adjust the handling and calibration procedures accordingly The BAND_MODE field in the catalogue file reflects whether only 3A 3B or both are present in the image In the detail sensor configuration file for example NOAA 15 cfg there is a master switch which informs SeaShark that this sensor is an AVHRR 3 type instrument NOAA KLM_flag Y It is advisable when you set the above flag that you also set the NOAA KLM_format_IMAGE flag as this turns on the new features in the IMAGE file NOAA KLM_format_IMAGE Y It is also possible to set the NOAA KLM_flag when the instrument is not an AVHRR 3 type instrument This is not advised for normal processing though the effects of defining multiple slope intercepts for the visible channels can be interesting one can easily threshold the raw Page 85 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2
34. scan line If all three counts are different the median middle value is used SeaShark then calculates one averaged slope and intercept pair per 50 scan lines and uses inter polated values for the intermediate values This method reduces the effects of transient spikes 6 12 1 Calculation of Spectral Radiance We first calculate the at sensor spectral radiances using the formula L l c A 1 x CN 1 e B l c fori 3 4 5 where A D Slope value for band i line B 1 Intercept value for band i line CN c digital count for the pixel at coordinates J c A non linearity correction is then needed If radiance correction terms are available the correc tion takes the form 2 lin RAD AR BR C lin where A B and C are the correction coefficients and Rj is the linear radiance calculated above If these correction coefficients are unavailable a brightness correction method is used explained below Page 84 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 Brightness temperature is the weighted mean of the Planck function over the spectral response function of the channel The spectral response functions for each channel are stored as a table in the detailed sensor configuration file for the satellite SeaShark generates a brightness tem perature to radiance look up table for each of the 3 IR channels the resolution of this table is 0 1 K SeaShark then searches t
35. the behaviour of an object is dependent on data outside the object this data is not to be modi fied by const member functions Rule 25 A class which uses new to allocate instances managed by the class must define a copy con structor Rule 26 All classes which are used as base classes and which have virtual functions must define a virtual destructor Rule 27 A class which uses new to allocate instances managed by the class must define an assignment operator Rule 28 An assignment operator which performs a destructive action must be protected from performing this action on the object upon which it is operating Rule 29 A public member function must never return a non const reference or pointer to member data Rule 30 A public member function must never return a non const reference or pointer to data outside an object unless the object shares the data with other objects Rule 31 Do not use unspecified function arguments ellipsis notation Rule 32 The names of formal arguments to functions are to be specified and are to be the same both in the function declaration and in the function definition Rule 33 Always specify the return type of a function explicitly Rule 34 A public function must never return a reference or a pointer to a local variable Rule 35 Do not use the preprocessor directive define to obtain more efficient code instead use inline functions Rule 36 Constants are to be defined using const or enum never using define Rule 37 Avoid t
36. the medium used 59 73 14 ASCII SYYMMDDhhmmPPT where S sensor YYMMDDhhmm format date PP platter if optical disc used T type D lt E xabyte endline 73 74 1 Table 5 31 Format of the Report Line of the Distribution Report Page 65 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 The report line of the Media Report is formatted as in Table 5 32 E Start Stop Size in No Name Short Description P Type byte byte bytes 1 date date of the operation 1 10 10 ASCII YYYY MM DD blank 11 11 1 2 media_ID id of the medium 12 27 14 ASCII SYYMMDDhhmmPPT where S sensor YYMMDDhhmm format date PP platter if optical disc used T type D It E xabyte blank 28 28 1 3 media_type type of the medium 29 32 4 ASCII e g OPT blank 33 33 1 4 media_stat status of the medium 34 43 10 ASCII e g created blank 44 44 1 5 archive_num reference number of the 45 58 14 ASCII media in the archive endline endline character 59 59 1 Table 5 32 Format of the Report Line of the Media Report 5 9 Configuration File Format The format of a configuration file is described below a configuration file contains a number of lines each line is either a comment line which is ignored by the software or a configuration line which is read by the software a comment line is any line whose first two non space characters are
37. will only write up to a maximum 1000 bytes of this data into the file This means up to 27 preflight slope intercept and break points per channel can be stored in the IMAGE file far more than normally required A look up table for the calibration of channels 1 2 and 3A has been added to the FILE_DESCRIPTOR_RECORD starting at byte 3013 The results in the look up table are scaled into 16 bit words these three scale factors and offsets are written in 6 16 bit words channel 1 2 3A scale factor 1 2 3A offset from byte 3001 The scale factors are configura ble and are defined in the detailed sensor configuration file for the satellite The values in the look up table can be helpful for approximate long hand calculations The changed section in the FILE_DESCRIPTOR_ RECORD is shown below Short Start Stop Size in No Name ee Type Description byte byte bytes blanks 991 calibra calibration coeffi long tion coef cients ficients LUT scale factor for short band 1 LUT scale factor for short band 2 LUT scale factor for short band 3A LUT offset for band short 1 LUT offset for band short 2 LUT offset for band short 3A CH1 LUT LUT for band 1 unsigned short CH2 LUT LUT for band 2 unsigned short CH 3A LUT for band 3A unsigned short LUT Table 6 3 Extract from the NOAA KLM FILE DESCRIPTOR RECORD Page 87 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue
38. window and a simple naming convention has been adopted to indicate this e g the ZoomCallbacks_c class contains the static callback functions for the ZoomWindow_c class All the class declarations are written to a header file which is generated by WorkShop Visual shark H Each class has a create function which deals specifically with widget crea tion These functions are written to another WorkShop Visual generated file shark cc as is the main function and any code fragments which have been entered into WorkShop Visual directly All other functionality is encapsulated in separate modules The main function initialises the X Windows environment for the application and creates instances of every window class and callback class used in SeaShark Finally the program enters the polling loop for X Windows applications and waits for the X Server to supply appropriate X Events to the SeaShark client when they occur e g when a PushButton widget is selected Page 89 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 7 2 List of Modules This chapter gives an overview of the modules which make up the SeaShark software The overview is given as tables containing for each module its name and a brief description of its function Modules are divided into the following types e Processes These are physical design elements They form the backbone or infrastructure of the SeaShark system and as such are only run as p
39. within the SeaShark design A task can be defined as an item of work which SeaShark must perform A task has an independent identity separate from the product or order from which it is derived Two types of task a Product Task and an Order Task are recognised by the system e A Product Task concerns the generation of Level 1 products from Level 0 data This is rou tine processing which is carried out on every HRPT data set entering the system For such products a task is automatically generated e An Order Task concerns the generation of products such as Fast Delivery products requested in user orders Order Tasks are automatically generated when new orders are entered into the system either when they are received in an incoming network directory or when they are manually entered Page 26 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 3 13 2 Storage A task appears in two places within SeaShark e On disc Disc versions of tasks are held in the Task Store which is a directory in the data area Each task is held in a separate file The Task Store is split into two sub directories called Product and Order Tasks within the Product directory are labelled with the product ID Tasks in the Order directory are within directories labelled with the order ID containing tasks labelled with order and sub order ID s concatenated Task files store a major and minor software version number This is used to provide comp
40. written to the tape from where they can be retrieved at a later date The tape contains a number of files which have been written to the tape in Unix tar format The sequence of the files on the tape 1s shown in Table 5 37 Name Short Description Format Label Era identifier Unix tar Directory 1 First HEIO Unix tar Directory 22 Second directory Unix tar Product_n nth archived product Unix tar Directory_n nth directory Unix tar Table 5 33 Archive Tape Format Note the Label and Directory tar files contain a single file named SeaShark dir The Product tar files contain a number of files as detailed below The first file provides a label which is used to identify the tape and distinguish different tapes in the archive Following the label there are a series of file pairs The first file of a pair contains an archived product whilst the second contains a directory of the products on the tape up to that point As new products are appended to the tape the directory is extended to include their details page 68 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 When untarred from the tape a Label File has the format of Table 5 37 Short Start Stop Size in No Name ree Type Description byte byte bytes 1 Header Identifies the tape as 1 13 ASCII a SeaShark archive SeaSharkDIR tape 2 Identifier Distinguishes differ ASCII of the form e
41. 0 e SeaShark e Create_Land_Sea_Mask e Extract _Calibration_Data e Generate_AVHRR_Quicklook AVHRR e Generate_SeaWiFS_Quicklook SeaWiFS e Interpolate_Navigation_Data e Update_AVHRR_CatEntry AVHRR e Update_SeaWiFS_CatEntry SeaWiFS 6 4 Archive The files created at the Levell stage are copied onto archive tape Files updated are e catalogue iuf e lt Tape_id gt Refer to Table 5 22 Archive Tape index file data record on page 55 For the catalogue iuf the amendments are e MetaLinel e Archive centre e Archive tape id e Media type id Executables used are e SeaShark e Exabyte 6 5 Delete Any files or directories relating to the product are deleted from disk 6 6 Retain The product is changed to a Levell archive product from which distribution products can be created 6 7 Orbit Stitching There are two stages to orbit stitching the first is calculating whether two or more passes can be successfully joined stitched together and the second is to perform the stitching Stage 1 Potential Stitch_Passes Identifies passes from different ground stations which are susceptible to being stitched into a more complete orbit according to timing criteria Page 80 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 Stage 2 Stitch_Passes Using the information ascertained from Stage 1 several passes from different ground stations are combined to form a more complete orbit with
42. 032 16 Latitude cdd mm 54 6 ASCII where c compass direction dd degrees mm minutes 17 space space 55 1 ASCII char 032 18 Longitude cddd mm 62 7 ASCII where c compass direction ddd degrees mm minutes 19 space space 63 1 ASCII char 032 20 start date dd mmm yy 72 9 ASCII where dd date mmm month yy year 21 space space 73 1 ASCII char 032 22 end date dd mmm yy 82 9 ASCII yy year Table 5 25 Order file data Record Page 60 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 as Start Sto Size in No Name Short Description P Type byte sel Bytes 23 space ASCII char 032 24 start time hh mm ss where hh hour mm minute yy year 25 space space ASCII char 032 26 stop time hh mm ss ASCII where hh hour mm minute year 27 space space ASCII char 032 28 Pass identi archive product id ASCII fier 29 space space ASCII char 032 30 Order type Order type ASCII 31 Media type Media used for delivery ASCII 32 Product Product type e g L1B or ASCII type LFD1 etc 33 Priority Priority ASCII 34 Product sta Product station e g VEG ASCII tion 35 space ASCII char 032 36 Destination ASCII code 37 space ASCII char 032 38 Shipping 138 ASCII code 39 space 140 ASCII char 032 40 Comments 218 ASCII 42 new line 219 219 ASCII char char 012 Table 5 25 Order file data Record 5 7 Level 2 Distribution Product Level
43. 1 Interface sub directories 2 noes Seal ta ae Gee A 7 Figure A 12 Processing Steps Sub dIreCtor es s 5cicacs0i49 ccseascecenaas sa saqdecdvaseuagsaceasaaseeeateion sd A 8 Figure A 13 Product sub dre clon daetitied eee aera edged ede A 9 Figure A 14 orbit data sub directories setos ii A 10 Figure A 15 Processes sub directories ccesscesscseeserscecssscecosneccetsacessecseeeccenteccessens A 10 page xi SeaShark Detailed Design Document INTRODUCTION SHK DDD 001 Issue 2 0 1 INTRODUCTION 1 1 Purpose To document the detailed design of the SeaShark software This document is intended to be read by parties interested in the software development of Sea Shark including ESRIN which wishes to ensure that the software will encompass a complete and consistent set of functions e VEGA the developer of SeaShark which wishes to ensure that the scope of the software is well defined and that the software will be testable 1 2 Scope The SeaShark project will develop software to provide a capability for the processing archiv ing and dissemination of data from the SeaStar and NOAA satellites The software will be installed at several acquisition stations of the European Co ordinated Tiros Network it will provide an environment in which the data processing can be easily carried out by trained oper ators On a regular basis 1 3 Definitions Acronyms and Abbreviations This section lists the definitions of all terms acr
44. 2 SeaWiFS distribution products are formatted as specified by 43 The formats of the AVHRR Level 2A and Level 2B distribution products are as defined in 21 Page 61 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 5 7 1 IMAGE File Refer to 20 5 7 2 LEADER File Refer to 20 5 7 3 NULL_VDF File Refer to 20 5 7 4 TRAILER File Refer to 20 5 7 5 VDF File Refer to 20 5 7 6 Distribution Tape Index File The tape distribution index file is created on distribution an order See Table 5 26 and Table 5 27 Short Start Stop Size in Type Description byte Byte Bytes yP Identifies file 18 18 Distribu tion Report 19 ASCII char 012 Table 5 26 Tape distribution index file header Record Short Start Stop Size in No Name Ka Type Description byte Byte Bytes 1 Productid The order id 1 16 16 ASCII Archive The id of the ASCII product id levell product start time Either in ASCII HH MM SS or location stop time Either in ASCII HH MM SS or location Order type The order type ASCII The date the order ASCII was distributed ASCII char 012 Table 5 27 Tape distribution index file data record Page 62 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 5 7 7 Order status file Refer to Section 5 6 7 5 7 8 Order file Refer to Section 5 6 8 5 8 Report File A report is a text file which
45. 3 13 Order errors 3 14 5 Failed Order Directory If an order is received which has a missing or corrupt order code and or sub order number it cannot be identified so no directory can be created for it on the system Also because the order cannot be identified a status file cannot be written To prevent the order being deleted and lost completely it is copied to a directory at the location specified by the failed_order_directory tag in the SeaShark cfg file Rejected orders for which no status file may be written are copied to this directory and named using an incrementing counter e g FAIL000001 A message is written to the shell when this happens so that the error and its associated FAIL file can be matched In the case of multi order files only the rejected sub order is copied not the whole multi order file If no location is specified in the Sea Shark cfg file or the specified directory does not exist the failed order directory is not used and rejected orders are deleted action 1 above It is the operator s responsibility to empty this directory when necessary The directory is not polled 3 14 6 Multi Order Files A multi order file is an ESA Order File which contains more than one ESA Order Each order in a multi order file is processed individually This prevents the whole multi order file from being rejected whenever an error is detected in a single order 3 15 Archive Products 3 15 1 Physical Design Refer to Table 3 7
46. 4 28 October 1997 SeaShark SeaWiFS Level 2 Processing Guide to Products SHK GTP 001 9 February 1998 HME SeaWiFS HRPT Data Format SHK ICD 005 17 June 1999 Overview The document follows the guidelines laid down in the ESA Software Engineering Standards PSS 05 02 3 After this introduction the document is divided into a number of major sec tions which are briefly described below 2 GENERAL DESCRIPTION This section outlines the standards which will apply to all software developed within the project 3 PHYSICAL DESIGN This section describes the physical design of SeaShark i e how the system is divided into physical design elements such as processes and how those pro cesses communicate with each other 4 PROCESSING INTERFACE Defines how SeaShark executes processing tasks Some are automatic others require operator intervention 5 FILE FORMATS Defines the file formats used within SeaShark 6 PROCESSING STEPS Describes the various stages of data processing which SeaShark is capable of 7 COMPONENTS This section gives an overview of the GUI and the modules and classes which make up the SeaShark software Page 4 SeaShark Detailed Design Document GENERAL DESCRIPTION SHK DDD 001 Issue 2 0 2 GENERAL DESCRIPTION This section defines the standards which will apply to all software developed within the project 2 1 Design Standards Booch standards have been followed in the architectu
47. 5 5 13 Stop_Synch_ Stop synch pixels for the 8 bands 21493 21508 16 unsigned 8 Pixel short Table 5 4 Format of the SeaWiFS Level 1 Image Data Record Start Stop Size in No Name Short Description byte byte bytes Type Times 1 Band 1 of the SeaWiFS sensor unsigned short 2 Band 2 of the SeaWiFS sensor unsigned short 3 Band 3 of the SeaWiFS sensor unsigned short 4 Band 4 of the SeaWiFS sensor unsigned short 5 Band 5 of the SeaWiFS sensor unsigned short 6 Band 6 of the SeaWiFS sensor unsigned short 7 Band 7 of the SeaWiFS sensor unsigned short 8 Band 8 of the SeaWiFS sensor unsigned short Table 5 5 Format of the SeaWiFS Image_data Structure Page 45 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 The AVHRR imagery file contains a number of Image Data records each of which is formatted as described in Table 5 6 AER Start Sto Size in No Name Short Description P Type Times byte byte bytes 1 Scan_Line_F Scan line flag 1 2 2 unsigned 1 lagl short Scan_Line_ Scan line day Day of Year unsigned 1 Day short Scan_Line_T Scan line time millisecs of day unsigned 2 ime short Spacecraft_I Spacecraft Identifier 2 x 16 bit unsigned 2 D words short Spacecraft_T Spacecraft time tag 4 x 16 bit unsigned 4 ime_Tag words short Telemetry Spacecraft calibration telemetry unsigned 10 short B
48. 9 ASCII top_time archived pass can be YYYY MM DD hh mm ss different from field 4 blank 108 108 7 status 109 116 8 ASCII e g acquired blank 117 117 1 Table 5 30 Format of the Report Line of the Acquisition amp Archiving Report Page 64 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 Start Stop Size in byte byte bytes media_ID medium identifier 118 131 14 ASCII SYYMMDDhhmmPPT where S sensor YYMMDDhhmm format date PP platter if optical disc used T type D It E xabyte Type Name Short Description endline 132 132 1 Table 5 30 Format of the Report Line of the Acquisition amp Archiving Report The report line of the Distribution Report is formatted as in Table 5 31 Ae Start Sto Size in No Name Short Description P Type byte byte bytes 1 date date of the operation 1 10 10 ASCII YYYY MM DD blank 11 11 1 2 order_ ESA order code 12 21 10 ASCII AAADDDD YY blank 22 22 1 3 sub_order_ ESA sub order 23 26 4 ASCII nnnn blank 27 27 1 4 sub_order_s status of the sub order 28 32 5 ASCII tat e g done or error blank 33 33 1 5 pass_id passage identifier 34 53 19 ASCII YYMMDDhhmmaass where aa acquisition station ss sensor blank 53 53 1 6 Prod_type type of distributed prod 54 57 4 ASCII uct as defined by EPOORD blank 58 58 7 media_ID id of
49. EAD Read archive product request acknowledgement token Exabyte TX_WRITE Write archive product request acknowledgement token Exabyte TX_DIST Write distribution product request acknowledgement Exabyte token TX_COMMAND Status request token Exabyte TX_EJECT Eject request acknowledgement token Exabyte TX_DIR Directory request acknowledgement token Exabyte TX_REWIND Rewind tape request acknowledgement token Exabyte TX_FORWARD_FILE Fast forward tape by one file request acknowledgement Exabyte token TX_BACKWARD_FILE rewind by one file request acknowledgement token Exabyte TX_WRITE_EOF Write end of file marker request acknowledgement token Exabyte TX_END_OF_MEDIA Move to end of tape request acknowledgement token Exabyte TX_MOUNT Mount optical disk request acknowledgement token TX_UNMOUNT UnMount optical disk request acknowledgement token TX_INITVOL Reserved TX_RECOVER Reserved TX_CD Reserved TX_DU Reserved TX_CHMOD Reserved TX_CHOWN Reserved TX_BACK Reserved TX_IMPORT Import product request acknowledgement token Processor TX_NAVIGATE Navigate product request acknowledgement token Processor Table 3 1 Inter Process Messages Page 14 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 Action Process TX_COAST_LINE_ADJUST Coastline adjust product request acknowledgement token Processor TX_LEVEL1 Level request acknowledgement token Pro
50. EOS AVHRRSHRFramePar represents the frame parameters from the scene header record of an AVHRR ams CEOS product Table 7 2 Classes Used by SeaShark Page 92 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 Class Name CEOS AVHRRSHRMissionPar ams Description represents the mission parameters from the scene header record of an AVHRR CEOS product CEOS AVHRRSHRProcessPar ams represents the process parameters from the scene header record of an AVHRR CEOS product CEOSLevel1PixelDescription CEOS AVHRRSHRSensorPar represents the sensor parameters from the scene header record of an ams AVHRR CEOS product CEOS AVHRRSHRScenePar represents the scene parameters from the scene header record of an AVHRR ams CEOS product CEOSBlankField used to create variable length blank segments in the FDR CEOS Calibration represents calibration data a slope and intercept within the radiometric cal ibration record Used internally by CEOSRadiometricAncillaryRec CEOSCorrectionInfo represents orbit correction information for the orbit record of SHARP CEOS products CEOSFDRFixedSegment represents the fixed segment at the beginning of a CEOS FDR CEOSFileDescriptor represents the file descriptor information which appears at the beginning of all CEOS format files CEOSFileID represents the record information parameters of a CEOS format file CEOSFlexFDR represents the FDR for SeaWiF
51. ID represents product identifiers which have a SeaShark standard format ProductOrder represents an ESA product order ProductTypeData handles lists of PushButton widgets for use in cascade menus PRTCountToTempCoeffs represents the NOAA table of coefficients for black body parameters PSPoint handles DCW clipping for postscript quicklook generation QIC QIC access functions RAEHeaderFile represents RAE tape format header file RawImage represents simple raw binary image files with no header Rectangle represents the mathematical concept of a rectangle which is used in many places in SeaShark for example in navigation ReportEntry common features of report entries Report provides functions for handling the various SeaShark reports including the reading formatting and writing of reports etc ReportCallbacks_c ReportHandler X callback functions for the Report Window of the GUI ReportWindow_c handles report generation functionality associated with the Report Window of the GUI ResourceManager provides generic storage mechanism in a directory structure defined by a set of keys ResourceManagerl Key a resource manager which uses one key to differentiate between esources The key provides the file name in which to store the resource ResourceManager2Key a resource manager which uses two keys to differentiate between resources Key 1 directory name key 2 file name Used internally by ResourceMa nager
52. IGN SHK DDD 001 Issue 2 0 e File Naming Conventions e Log Files Each program outputs a log file which indicate the success or failure of the processing By reading the log files SeaShark can determine the outcome of the processing and take appropriate action for example it can identify products which are in an incomplete state and reset them It can cancel later processing steps File System Communication is the means by which programs exchange information with each other Most programs in the processing chain write data files which are read by a later step in the chain In addition to the directories described all files related to the same product are stored in a sub directory named with the product id In order to distinguish different files there is a set of file naming conventions The directory and file naming conventions described above make it possi ble to detect inconsistencies in the state of the system The control mechanisms are simple and are easily managed by the operator In the event of serious system problems it is possible to recover by examining the contents of the directories and resetting to a known state by copying or deleting appropriate files Automatic control by the system is the normal state of affairs whilst manual intervention is expected to be an uncommon event 3 7 Directory Structure SeaShark uses a hierarchy of directories in which it stores different types of information The hierarchy is designed to
53. Import used while the product is being imported e LO used prior to navigation e L1 Arch used after navigation Status The processing activity flag for the product The following values are used used for archived products where no further processing is possible Ready the product is ready for further processing Queued the product has been added to the Immediate queue for processing Error something went wrong with the last processing step Active the product is undergoing processing Batch the product has been added to the Batch queue and is awaiting the start of the next batch job To The next stage of processing for the product The following values are used e Import e Navigate e Coast line adj Page 36 SeaShark Detailed Design Document PROCESSING INTERFACE SHK DDD 001 Issue 2 0 e Level 1 e Delete e used for archived product 4 1 3 Counting The Products On The System The Main window contains a count of the number of products on the system 4 1 4 Selecting Processing Steps A product can be progressed through the five processing steps by operator intervention The required steps can be selected using the Processing Steps toggle buttons in the Task List win dow Selecting the Process button will cause a Confirm window to appear and the selected processing steps will commence when a queue is selected 4 1 5 Viewing The Image A non active product can be displayed at any stage using the Display
54. RPT image i e good bad missing etc HRPTSpacecraftID represents the Spacecraft ID field which is common to all HRPT images The field identifies which satellite the data is from and also the HRPT minor frame number of the current HRPT major frame HRPTTimeTag represents the time tag field which is common to all HRPT images The field defines the current day number Julian and the time in millisec onds since midnight of the first byte of HRPT minor frame HumidityClimDataLoader HumidityMetDataLoader functionality to ingest humidity climate data files into SeaShark functionality to ingest humidity meteorology data files into SeaShark HumidityQuery Manager functionality to interrogate the humidity data in the ancillary database Table 7 2 Classes Used by SeaShark Page 97 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 InitWindow_c Class Name Description ITEFCatalogue Update represents IEF catalogue batch update file IEFTrailer represents the IEF catalogue trailer Image top level level class of all the images that are either generated or accessed within the SeaShark application ImageAverage represents an averaged image parameter from a sequence of consecutive image scan lines ImageDisplayRect represents a rectangular area of a displayed image ImageGridDimensions represents the specification of the size width height spacing etc of a grid of data associate
55. S L2 flexible format products CEOSGCPRecord represents the GCP record of a SHARP CEOS product CEOSGenericRecordID base class for CEOS record IDs CEOSHistogramData represents histogram data for CEOS SHARP level 1 products CEOSHistogramRecord represents histogram records for CEOS SHARP level 1 products CEOSImageParameters represents the image parameters in the FDR of a SHARP image CEOSLevel2PixelDescription CEOSLevel1 SharpImageVarSeg represents the CEOS pixel description field for SHARP L1 FDRs represents the CEOS pixel description field for SHARP L2 FDRs CEOSLevel2SharpImageVarSeg represents the variable segment of a SHARP L1 CEOS image FDR represents the variable segment of a SHARP L2 CEOS image FDR CEOS MapProjectionData CEOSLINNDescription represents the LINN description field of a SHARP L1 image FDR CEOSLocatorFields represents the locator fields part of the variable segment of FDRs CEOS MapProjectionRecord CEOS MeanBrouwerElements represents the map projection data for SHARP CEOS products represents the map projection record for SHARP CEOS products represents the mean Brouwer orbital elements for SHARP CEOS products represents the NULL VDF of CEOS products CEOSNull VolDirFile CEOSOrbitParameters represents the orbital parameters for a SHARP CEOS product CEOSOrbitRecord represents the orbit record for a SHARP CEOS product CEOSOriginalTBUS represents the original TBUS information in
56. SHARP CEOS products CEOSOriginalTLE represents the original TLE information in SHARP CEOS products CEOSParameter represents a parameter within the radiometric ancillary record Used inter nally by CEOSRadiometricAncillaryRec CEOSPixelGroupParameters represents the pixel group parameters of a CEOS product Table 7 2 Classes Used by SeaShark Page 93 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 Class Name Description CEOSPrefixData represents the image prefix data in every line of a SHARP CEOS image CEOSPrefixSuffixLocators represents the prefix and suffix locator field part of the SHARP image FDR CEOSProdDocInfo represents the record information parameters of a CEOS format file CEOSProdIdInfo represents the record information parameters of a CEOS format file CEOSProdIdVolNumberInfo represents the record information parameters of CEOS files CEOSProduct abstract base class for all CEOS products CEOSRadiometricAncillaryRec represents the radiometric ancillary record of the SHARP Level 2 leader file Ref 21 CEOSRecordID represents the record identification segment of CEOS products CEOSRecordInfoFields represents the record fields of AVHRR SHARP FDRs CEOSRecordParameters represents the record parameters of a SHARP CEOS product CEOSSatelliteInfo represents the satellite information record which is part of the Leader file of the SeaWiFS LAC 1A distribution produc
57. SHK REP 003 1 0 9 September 1994 SeaShark System Specifications Reporting DPE OT JMM 93 001 Issue1 4 SeaShark System Specifications Annexes SeaS GS AN 00 Issue 1 0 20 April 1993 Programming in C Rules and Recommendations Ellemtel document M900118 dated 27 04 1992 Effective C Scott Meyers Addison Wesley ISBN 0 201 56364 9 The Annotated C Reference Manual M A Ellis amp B Stroustrup published by Addi son Wesley 1990 Two Line Element Set Format Description SPACECOM NASA date unknown Tbus format APT Information Note February 1981 EPOORD Ground Station Interface Specification SH3 EPO SER 00 006 Issue 3 2 26 June 1995 Orbit Stitching Philosophy ESRIN fax 27 March 1995 Page 3 SeaShark Detailed Design Document INTRODUCTION SHK DDD 001 Issue 2 0 38 39 40 41 42 43 44 45 1 5 SeaStar Spacecraft L Band Downlink to Receiving Stations Interface Control Document Orbital Sciences Corporation 22 April 1996 NOAA Technical Memorandum NESS 107 Rev 1 Frame Formatter Level 0 output file format version 1 1 by Frederick S Patt NASA April 16 1993 updated by B Franz September 1997 Tools h Foundation Class Library for C Programming Version 7 Rogue Wave Software Inc 1996 SeaShark Instrument Data Product Format FDP Generic Format SHK ICD 003 27 November 1996 SeaShark Instrument Data Product Format SeaWiFS Flexible Format SHK ICD 00
58. Slope of calibration for band 3 int 1 Slope of calibration for band 4 int 1 7 Band5_ Slope of calibration for band 5 21 24 4 int 1 Slope Table 5 20 Format of the Calibration Data Record Page 52 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 Band3_ Intercept Short Description Intercept of calibration for band 3 Size in bytes Type int Band4_ Intercept 10 Band5_ Intercept Intercept of calibration for band 4 Intercept of calibration for band 5 33 int int Table 5 20 Format of the Calibration Data Record Slope values are multiplied by 2 before being stored in the 4 byte integer Intercept values are multiplied by 22 before being stored in the 4 byte integer 5 4 6 Quicklook Product The quicklook product is in standard Sunraster 24 bit RGB format 5 4 7 Postscript Quicklook File The postscript quicklook file is a hardcopy summary of the product The file is in Adobe post script version 1 0 format and adheres to the specification in 30 An example postscript quicklook file is shown in Figure 5 2 Page 53 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 Vega Logo Product ID Satellite ID Date Start Time Stop Time Product 9206291329VEN1 NOAA 11 920629 13h 29 29 13h 41 28 Details Coverage Map Catalogue Catalogue Info Station VEG Direction Ascending
59. Ta esa esrin SeaShark Detailed Design Document Doc Ref SHK DDD 001 Issue 2 0 Date 17 June 1999 SeaShark Detailed Design Document SHK DDD 001 Issue 2 0 Document No Issue No SeaShark Detailed Design Document SHK DDD 001 2 0 Date 17 June 1999 Distribution P Goryl ESRIN J M Melinotte ESRIN Summary SeaShark will provide a capability to process archive and disseminate data acquired by the Seastar SeaWiFS and NOAA AVHRR sensors Authors C L Aspell S J Newby J E Rickards J Mitchell M R Lever J W Treloar VEGA Signed S J Newby A T E E Date Reviewed T Stephens Ma ed Date Authorized C P Winder MW eke cig ate este ea ete ates Date Accepted ESA Responsible Joo Date page ii SeaShark Detailed Design Document SHK DDD 001 Issue 2 0 Document Status Sheet Issue Date Details Author Draft A Document created Draft B 17 Mar 97 Updated to include Phase 2 amp Phase 3 functionality C L Aspell Draft D 13 Mar 98 Add all missing sections MR Lever Issue 1 0 30 Jun 98 Formal issue M R Lever Issue 2 0 17 Jun 99 Updated to describe support for HMF SeaWiFS HRPT S J Newby page iii SeaShark Detailed Design Document Table of contents SHK DDD 001 Issue 2 0 Contents Document Status Sheet vecinita iii 111 Contents st a A A A A arated alle desiads iv Eristof Tables sti iin a a A A da AA E ix List of A RO xi Section 1 INTRODUCTION ssesess
60. The Order Store ieman eter E edie eee 37 420 The Operator nterface eorr i es 38 4 2 6 Counting The Orders On The System oooconocccnoconooncnoncnonccannnonn cono ncnonennnos 38 4 2 7 Viewing The Status Of Orders oooooccccnocccooocccoononononanononcnononcncnnnnncnnaninnnanos 38 4 2 0 Initiating Order ProCes sie a ds 39 4 2 9 Viewing Full Order Details vais idas 39 4 2 10 Entering New Ordets aa 39 SeaShark Detailed Design Document Table of contents SHK DDD 001 Issue 2 0 4 3 Immediate and Batch Processing sisiscssisecisssicassdecedasasusescevscndencasccseseadessdetoasseadens 40 Section S FILE FORMATS siscssscecssesscossdecedsssssedsseddsoaseessoosobssdedscvesswsdeessdssececssooscbeadsceeeed 41 5 1 AVHRR HRPT Product vc jaen osa 41 5 1 1 AVHRR HRPT Level 0 File Formats ooooccoococcnoccccnocccooncnononaconnncnonancninns 41 5 1 2 AQTINGDAT File Format a 42 5 2 Sea WIES HRP IT Producida 42 5 3 SeaWiFS HRPT Level 0 File Formats assi dali arcaicas 43 5 4 SeaWiFS and AVHRR Level 1 Archive Product ooocnococonoccconccccooncnononcnonnncnnnnnos 44 SAT Imagery Fil aia ass 44 542 Navigation Data File ta 47 5 4 3 Land S a Mask Pile astra 49 JA Coastline Fileas 12s cees a E N EE R 50 5 4 5 Calibration Data File AVHRR Only cooococcncccccnoccconoccconnnccnonanonancncnnaninns 52 5 4 6 Quicklook Product simsai iniii ae E E E EE 53 5 4 7 Postscript Quicklook File s jss ssaccs evedhagueadvessdensscdeuncueces sacs asnfebedtecsanseean
61. Values for 01 08 2000 Note holben values for 2nd range 500 1023 counts are defined thus Holben_valuesl 0 60 38 0 0 42 39 9 0 42 39 9 Values for 01 08 97 0 63 37 9 0 43 39 3 0 42 39 9 0 68 37 8 0 45 39 1 0 42 39 9 0 71 37 8 0 46 39 0 0 42 39 9 Values for 01 08 2000 The final configurable parameters which are needed are the integrated solar spectral irradiance and equivalent width of the spectral response function in micrometers So like for channels 1 and 2 we need entries in the NOAA 15 cfg file channel _W 0 246 channel F 2040193 L3 L3 Note at this time no calibration data exists for NOAA K and the above values are just for dem onstration purposes 6 13 2 Changes to the IMAGE file Extra calibration information for NOAA K is now available in the image file FILE_DESCRIPTOR_RECORD From byte 2001 the break points slopes and intercepts are listed in the following format Page 86 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 Break Point value 1 to n for band 1 Break Point value 1 to n for band 2 Break Point value 1 to n for band 3A Slope Value for range 1 to n for band 1 Slope Value for range 1 to n for band 2 Slope Value for range 1 to n for band 3A Intercept Value for range 1 to n for band 1 Intercept Value for range 1 to n for band 2 Intercept Value for range to n for band 3A Where n is the number of slope intercept pairs defined in the SeaShark cfg file SeaShark
62. WiFS tle AVHRR tbus b and c AVHRR only 5 11 2 Distribution Tape Product Files A distribution tape provides a means for delivering products to users A distribution tape con tains a number of files which have been written to the tape in Unix dd format The sequence of page 70 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 the files on the tape is shown in Table 5 38 Name Short Description Format Label Product 1 First distribution product Product 2 Second distribution product Product n n th distribution product Table 5 38 Distribution Tape Format The Label File is a simple 12 character text file of the format AAAddddddnnn where AAA 1s the station ID dddddd is the date in Y YMMDD format nnn is a unique tape number for that day Several files together form a single distribution product They are written anonymously to tape in the order specified by the corresponding product definition document The distribution product file formats are as defined in earlier sections page 71 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 6 PROCESSING STEPS 6 1 Import Import is the process of adding products to SeaShark 6 1 1 HRPT import The HRPT import process for AVHRR and SeaWiFS is very similar SeaShark can import three different types of AVHRR HRPT and three types of SeaWiFS HRPT The stages of import are 1 The i
63. WiFS level 2 distribution product SeaWiFSL2FlexProduct represents a SeaWiFS level 2 flexible format CEOS product SeaWiFSLAC1BProduct represents a SeaWiFS level 1B CEOS product SeaWiFSLAC2BProduct represents a SeaWiFS level 2B CEOS product SeaWiFSLevell Image definition of the level 1 SeaWiFS image data format within the SeaShark application SeaWiFSLevel1 Product represents the SeaWiFS data after it has been processed to level 1 product It provides functionality for Fast Delivery Product generation SeaWiFSLinelInterface provides a simple interface for processing level 2 data SeaWiFSStartSyncPixel used internally by SeaWiFSSyncPixels SeaWiFSSyncPixels represents the pixel field from the SeaWiFS HRPT Image and the SeaWIFS Level 1 image SeaWiFSRawProduct represents the SeaWiFS data after it has been imported and is ready for processing through to a full level 1 product Sensor common features of all sensors SHARK_Inet_Sock generic internet socket class SharpLevel1 Product represents a SHARP level 1 product SharpLevel2B Product represents a SHARP level 2B product SharpProduct abstract base class for SHARP CEOS products Table 7 2 Classes Used by SeaShark Page 102 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 Class Name Description SpacecraftSOH represents the spacecraft state of health data that is included in the SeaWiFS HRPT data stream and the imagery file of the SeaWiFS level 1 arc
64. a Level 1 Archive Product oooooconncocinococonncccnnnnncnnnnnonnnacononanononannnnnacinnnos 44 Table 5 4 Format of the SeaWiFS Level 1 Image Data Record coooococnnocccnnccccnonnccnonccinnnos 44 Table 5 5 Format of the SeaWiFS Image_data Structure oooooconoccccnoncccnonnncnoncnononccinnnacinnnos 45 Table 5 6 Format of the AVHRR Level 1 Image Data Record coocoococnnocccconcccnoncnonnnccinnnos 46 Table 5 7 Format of the AVHRR Image_data Structure oooococnnnoccnoncccnnnncnnonnnonnncncnnncninnnos 46 Table 5 8 Format of the Navigation Da A A eae 47 Table 5 9 Format of the Grid Dimensions Structure coooocccnnncccnoncccnoncnonnnnnononcnonananononecinnnos 48 Table 5 10 Format of the Grid Row Structure oooooononcccnoncccnoncccnnnnncnoncnonnnnnononcnonnncnnnncconnnos 48 Table 5 11 Format of the Grid Point Values structure ooooonocccnnccccnoncncnoncnononcnonnnaconananinnnos 49 Table 5 12 Format of the Land Sea Mask Record cooooooccnoccconcccconococooncnononcnononononnnccconnncnnnnos 50 Table 5 13 Format of the Classification Flags structure oooococnnococnoncccnoncnononccononcconnnaninnnos 50 Table 5 14 Format of the Coastline File c g s uch atadas 50 Table 5 15 Format of the Segment structure icccssiccisscctsasscejedetyessdadsvssedcatacastaacssndedecasacsanees 51 Table 5 16 Format of the Earth Extent structure oooooocnnncccnoncccnononcnnnnnononnnononcncnnncccnnnccnnnnos 51 Table 5 17 Format of the Image Extent structure oooooccnnncccnoncccnno
65. a covered by the image and stores them in a separate file The program Extract_Coastline is used Allows the operator to overlay the coastline on a displayed image and to move the coastline until 1t best matches the image The offsets needed to get a good match are written to a catalogue The programs Set_Coastline_Offset and Retransform_Coastline are used Renavigate Land Sea Mask Repeats the above NAVIGATE step taking into account the coastline offsets Adds Land Sea Mask data to the image The program Create_Land_Sea_Mask is used Extract Calibration data Interpolate Navigation data Extracts the calibration information from a Levell image The program Extract_Calibration_Data is used Interpolates the navigation data in the given file so that it has a grid line spacing exactly equal to 1 The program Interpolate_Navigation_Data is used Generate Quicklook Generates a quicklook image from a navigated Level product The program Generate_AVHRR_QuickLook or Generate_SeaWiF S_Quicklook is used Update Catalogue The program Update_AVHRR_CatEntry or Update_SeaWiFS_CatEntry is used Postscript Quicklook Converts the quicklook into a printable PostScript version with added information from the catalogue The program Generate_Postscript_QuickLook is used Table 3 3 Steps in the Archive processing chain Page 17 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 3 6 Distributi
66. a geographic coordinate For example when generating the land sea mask Page 75 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 6 2 3 Geographic location to pixel position This is not a simple problem and requires a complex two dimensional search in the navigation grid to find the corresponding pixel position The navigation grid is sub divided into two blocks the sizes of which are defined in the SeaShark configuration file The navigation grid data elevation and azimuth angles is then projected into polar stereographic projection to avoid all problems with the discontinuity in azimuth angles and the poles of the elevation angle For each block a set of affine coefficients is calculated This defines a mapping from pixel position to geographical position The affine coefficients are the coefficients from the equation x y Axo Bx Cxqx D Eyo Fy Gyoy H An example of a coefficient matrix is shown below Affinex LS SEE LEER OSOS so SSCS OSS gt ES oS SS SSS SSES SSS ESOS SS SSS SS SERES s Seeds POSES OSS OSS SSS ES OSS OSS OSS OSI ROK Kehoe SOS SSS TESS SESS SOS OCS OES SILLA OSES SES SSS SO SSS SOS OS SOSA CAL de SEIS SLS SR ISS AN SIGAS lt gt yblock number 30 xblock number Figure 6 2 Graphical representation of an affine coefficient matrix Once the affine coefficients have been calculated geographical positions ca
67. ackscan Backscan data unsigned 30 short Space_data Space data unsigned 50 short Sync Synchronisation word unsigned 1 short TIP_data TIP data unsigned 520 short Spare_words Unused space unsigned 127 short Image_data Image data Structure 2048 Table 5 7 Auxiliary_sy Auxiliary synchronisation word unsigned 100 short Short Description Band 1 of the AVHRR sensor Start byte Stop byte N A Size in A Band_1 Band_2 2 1 1 2 2 2 2 Band 2 of the AVHRR sensor 3 Band_3 Band 3 of the AVHRR sensor N A 4 Band_4 Band 4 of the AVHRR sensor 5 Band_5 Band 5 of the AVHRR sensor N A N A 2 unsigned 1 short Table 5 7 Format of the AVHRR Image_data Structure Page 46 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 5 4 2 Navigation Data File The Navigation Data File contains the values of latitude longitude sun elevation sun azimuth satellite elevation and satellite azimuth for a regular grid of points within the product The navigation data file is a binary file consisting of a header record followed by a series of data records holding the tie point information The header record is forced to be the same size as the data records to give the file a fixed record length The actual record length is dependent on the number of tie points that are calculated for each line It can be calculated as follows record_length sizeof line_status_info
68. ame Description AVHRRSharp1Image concrete class representation of AVHRR level 1 SHARP images AVHRRSharp2AImage concrete class representation of AVHRR level 2A SHARP images AVHRRSharp2BImage concrete class representation of AVHRR level 2B SHARP images AVHRRSpaceData represents AVHRR space data within AVHRR images AVHRRTelemetry represents the AVHRR telemetry fields within AVHRR images AVHRRTIPData represents the AVHRR TIP data field within AVHRR images BatchCallbacks_c X callback functions for the Batch Window of the GUI BatchQueue handler for the batch queue BatchWindow_c functionality associated with the Batch Window of the GUI BrouwerOrbitElements abstract base class to represent mean brouwer orbital elements Buffer provides buffering for device handlers BusyCursor functionality for a generic busy cursor Calibration represents the calibration component of the radiometric ancillary record of the SHARP level 2 leader file CalibrationCoefficients represents a single set of slope intercept values for converting AVHRR ther mal infra red count values into radiances CalibrationData represents the AVHRR calibration data in an AVHRR image CalibrationDataLine represents the AVHRR calibration data for a single image line CalibrationFields represents the AVHRR calibration data fields in an AVHRR image Canvas functionality for the GUI display canvas Catxxxx The Catxxxx classes describe parts of a Catalogue Entry A Catalogue Ent
69. apsulate global variables and constants enumerated types and typedefs in a class Rec 20 Always provide the return type of a function explicitly Rec 21 When declaring functions the leading parenthesis and the first argument if any are to be writ ten on the same line as the function name If space permits other arguments and the closing parenthesis may also be written on the same line as the function name Otherwise each addi tional argument is to be written on a separate line with the closing parenthesis directly after the last argument Rec 22 In a function definition the return type of the function should be written on a separate line directly above the function name Rec 23 Always write the left parenthesis directly after a function name Rec 24 Braces which enclose a block are to be placed in the same column on separate lines directly before and after the block Rec 25 The flow control primitives if else while for and do should be followed by a block even if it 1s an empty block Rec 26 The dereference operator and the address of operator amp should be directly connected with the type names in declarations and definitions Rec 27 Do not use spaces around or gt nor between unary operators and operands Rec 28 Use the c mode in GNU Emacs to format code Rec 29 Access functions are to be inline Rec 30 Forwarding functions are to be inline Rec 31 Constructors and destructors must not be inline
70. aried nature of the data sets the data directory is divided into a number of sub directories largely based on data type The top level division of the data direc tory is shown in Figure 3 5 data E catalogue counters DCW orbit data orders products reports tapes tasks telecom in telecom out telecom prepare NA AVHRR SeawiFS archive distribution FOP Import L1Dist Level Level Level2 Navigated Figure 3 5 Structure of the data Directory The contents of the directories are described in Table 3 6 Page 21 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 Directory Content catalogue SeaShark keeps a database called the catalogue which holds important details of each gen erated product There is an entry in the catalogue for each product The catalogue entries are held as separate files which are stored in a hierarchy of sub directories see below for more details counters SeaShark keeps an on going set of counter files for use in numbering orders and reports DCW Data for the Digital Chart of the World orbit_data SeaShark keeps a database of orbit data describing the position of the satellite at a given time The information is needed for the data processing Orbit data exists as a number of files and these which are kept in a number of sub directories see below for more details orders SeaShark keeps copies of all ESA product orders and their processing states here products SeaS
71. art of the SeaShark They provide general functions e Programs These are also the physical design elements These are application programs in the classic which each provide a specific piece of functionality The main difference between processes and programs is that the programs are standalone They do not form part of the infrastructure and can in fact be run independently outside the SeaShark system and interface Classes These are the logical design elements which form the bulk of the SeaShark code They are the fundamental building blocks which are the basis of SeaShark They are librar ies They are called by the programs and processes to carry out the processing of SeaShark Scripts These are support functions written not in a general application programming lan guage but in operating system specific language 7 2 1 Processes A list of the SeaShark processes is given in Table 7 1 Process Name Description SeaShark SeaShark graphical user interface processor Manages processing steps exabyte Queues and actions requests to an exabyte tape drive Table 7 1 SeaShark Processes 7 2 2 Programs A list of programs used by SeaShark is given in the Software User Manual 9 In the standard SeaShark installation the source code for the programs is stored in SEA SHARKHOME devsw sre product processing_steps Some processing functions for example archiving and retrieving are implemented within the SeaShark user inte
72. ass will be the same as the class name except that each separate word will begin with a lowercase letter and words will be joined using the underscore character For example CEOS _file_descriptor cc e Private data names Data which is private to a class will contain lowercase letters and will begin with an underscore character Individual words will be separated by the underscore For example _document_number e Method names Names of methods which access private data will be the same as the data name except that each separate word will begin with an uppercase character and words will be joined For example DocumentNumber Further words can be used if they further illus trate the nature of the method for example GetDocumentNumber e Libraries These will be named with the character string lib followed by the class name in lowercase letters For example libcatalogue a 2 4 Programming Standards Each source code file will include a standard module header as shown below Title sensor cc Project SeaShark Type Ct Version Author David Palmer Vega Group PLC Arden Grove Harpenden Hertfordshire England AL5 4SJ Date 23 11 94 Purpose Class used to represent a sensor SeaWiFS or AVHRR on board a satellite Comments Not under RCS configuration Known Bugs None RRR KKK KR KKK KKK KK KK KK inc
73. at is described by 42 Page 57 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 5 6 Level 1 Distribution Product The format of the SeaWiFS Level 1A distribution product is as defined in 24 The format of the SeaWiFS Level 1B distribution product is as defined in 25 The format of the AVHRR Level distribution product is as defined in 20 5 6 1 IMAGE File Refer to 19 5 6 2 LEADER File Refer to 19 5 6 3 NULL_VDF File Refer to 19 5 6 4 TRAILER File Refer to 19 5 6 5 VDF File Refer to 19 5 6 6 Distribution Tape Index File The tape distribution index file is created on distribution of an order See Table 5 26 and Table 5 27 5 6 7 Order Status file The order status file contains information on the status of the distribution product Refer to 35 for complete description No Name Short Start Stop Size in Type Description byte Byte Bytes yP 1 space space ASCII char 032 Order date ASCII ASCII char 032 Table 5 24 Order status file data Record Page 58 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 Short Start Stop Size in Type Description byte Byte Bytes yP Ground sta 11 ASCII tion space 12 ASCII char 032 ESA order 22 10 ASCI code Sub order leading zeros are 26 ASCII number not printed Order status leading zeros are 32 ASCII not printed Order prior Priority is from
74. ates the task in memory and on disk Page 30 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 In processor_handler SendToken sends the token to the processor process tasks are only used in the main SeaShark process When processor has completed navigation a token is sent to the processor_handler function RecievedToken Using the product ID contained in the token the relevant task is fetched using get_task If the navigation completed successfully the task state is set to Uninitialised and _process_type is set to the next processing step The next step depends on which task form toggle buttons have been pressed If no further processing was selected _process_type will be set to TypeCoastLineAdjust the schedule state set to None and the task removed from the process immediate queue Finally the task is updated in memory and on disk 3 14 Orders 3 14 1 Terminology The following terminology is used e An ESA Order File is a file containing ESA Orders e An ESA Order or Order is a request for product generation It is represented by a single line in the ESA Order File which defines the product to be generated in terms of reference prod uct ID and either centre latitude longitude or start and stop times See 36 for more details 3 14 2 External Interfaces Order handling at an acquisition station uses two external interfaces e the import of ESA Order Files from ESRIN e the return of Order Stat
75. atibility between the software and task files In memory Memory versions of tasks are held within the User Interface which maintains a list of all current tasks in the system The list is used in the Task and Batch windows to allow the operator to view select and initiate tasks Every task in memory has a unique identifier which is generated from within the TaskPool each task that is loaded into mem ory is given the next number in sequence Task identifiers are not stored at any time and are unique to each execution of SeaShark Tasks are only used by the SeaShark main process Task information required by other proc esses are passed via tokens Object stores are used for task lists and task queues Both structures are stored each time their contents changes allowing the system to recreate itself each time it starts up The object stores will contain only the list of subject ID s associated with them 3 13 3 Task Pool The TaskPool contains every task that is within SeaShark Storage is organised by saving each task in either the product or order task directory The interface is initialised with the full list of tasks within the system When the system is started the Task Pool reads every task within the task store and loads each into memory A verify process checks that each task has an associated product If it does not the task is removed A check is also made that each product has an asso ciated task A warning message is logged if t
76. ation into a disc file and the information is subse quently read by another process This mechanism is used for communication between the Process Steps and for communication between the Processor and Process Steps e Socket Communication is represented by dotted directed lines Socket Communication is a Unix specific mechanism which allows messages to be sent between different processes either on the same computer or on different computers It is ideally suited for the sending of small quantities of data System Call Communication isn t represented in the diagram but uses the Unix specific system function which allows the initiation of a program as a separate executable The mechanism is used by the Processor to initiate a Process Step 3 4 Inter Process Messages All inter process messages are initiated from within SeaShark which creates tokens that are transmitted to other processes The receiving process will then return to SeaShark either a copy of the received token or a TX_ERROR token Page 13 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 The messages exchanged between SeaShark and other processes are shown in Table 3 1 Action Message Type Description Process TX_MESSAGE Status request token Exabyte TX_READY Ready token Exabyte Processor TX_QUIT Exit request token TX_STATUS Status request token Exabyte TX_DIR_ENTRY Reserved TX_FORMAT Format request acknowledgement token Exabyte TX_R
77. awn will return an interrupted status and then it is up to the processor process to clean up after the processing step Page 25 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 If we used the first method the child process would exit in the normal way and the system could handle the termination in the same way as a processing failure However the second method is far simpler to implement and if the processing step is killed by the system an operator the same recovery procedure would be used Also the second method allows processing steps more free dom and does not impose restrictions on their implementation 3 12 Error Handling As an operational system SeaShark provides facilities for automatic error checking and recov ery These facilities make it easy in the event of many system problems for the operator to restart the processing There are inevitably some situations in which automatic recovery is not possible and which therefore need operator intervention to restore system integrity This will be done using some unix commands and not via the SeaShark interface For this reason the under lying structure of the software for example the directory structure has been kept simple The operator is assumed to be capable of acting on messages issued by the system This usually involves checking the directories for incomplete or missing process files deleting appropriate ones and renaming others to maintain system inte
78. button in the Task List window to bring up the Display window The desired image band can be selected from the band menu and the band displayed by selecting the Display button in the Display window 4 2 Order Processing 4 2 1 Polling The Import Directory As mentioned earlier SeaShark makes use of timers to trigger events On every timer expiry default 10 seconds the SEASHARKHOME data telecom in orders directory is read When a new ESA Order File appears in the Import directory it is checked for various errors see Table 3 13 If no problems occur the order is copied to the EASHARKHOME data orders Store directory and a Task appears in the Task List Window 4 2 2 Processing As processing of the ESA Order proceeds the OrderStatus File is modified to reflect the processing which has taken place When processing is complete and the products have been written onto a distribution media or into a telecom directory a Shipping Date and appropriate code are added to the Order Status File See 36 for specific field details 4 2 3 Sending Status Files A regular check is made for orders with a complete shipping date the time between each check 1s set in the Prepare Order Status timer Such orders are moved to the export directory and renamed with the file name SSNNNNNN sta where SS is the Station code and NNNNNN is a unique counter 4 2 4 Purging The Order Store After completion ESA Orders are kept on the system for a predetermined
79. cessor Message Type Description TX_FDP FDP request acknowledgement token Processor TX_LEVEL2 Level2 request acknowledgement token Processor TX_LEVEL1DISTRIBUTE Level distribution product request acknowledgement Processor token Table 3 1 Inter Process Messages A standard format is used for the messages and this is shown in Table 3 2 Field Name Description _tx_command Message type Command contents _error_code Error code Error string _return_address Return address Product id _product_file_list List of files in product directory Location of product directory _sensor_info Sensor type Device name _dest_device_type Destination device type _sub_order_id Sub order id Table 3 2 Inter Process Message Format Messages of different type contain arguments which are appropriate for the function 3 5 Archive Processing Chain The SeaShark processing is designed as a number of steps which are executed in sequence thus forming a processing chain In this section the different steps in the processing of a raw HRPT image into a full SeaShark level 1 archive product are detailed Each step has been implement as a standalone program which is called in the correct order by the main SeaShark program Having each processing stage as separate executable allows any step to be repeated by the operator simply by running the program on the command line It also allows ESRIN to easily replace any step with a ne
80. code cartographic projections SeaDAS SeaDAS source code HDF and SeaWiFS calibration Xpm code X window pixmap library bin SeaShark executables configuration files data data files used by or generated by SeaShark Documentation c i o help help text files for the GUI one file per window header files used in software development install Install files library files used in software development sr source code files used in software development Data used for verifying import was successful Table 3 5 SeaShark Directory Content 3 7 2 Structure of the config Directory The config directory contains all the configuration files including the X resources database used by SeaShark A number of configuration files are used to divide the configuration data into functionally related areas Under the config directory there is one sub directory sensors in which configuration data related to a given sensor is stored There is a generic file Sen sor cfg which contains information applicable to all sensors and a file for each sensor which contains parameters describing the performance of that sensor information which is an impor tant input to the processing algorithms Page 20 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 3 7 3 Structure of the data Directory SeaShark generates and uses data sets of many different types all of which are stored in the data directory Because of the v
81. con stant and variable in a class library is to begin with a prefix that is unique for the library Rule 13 The names of variables constants and functions are to begin with a lowercase letter Rule 14 The names of abstract data types structures typedefs and enumerated types are to begin with an uppercase letter Rule 15 In names which consist of more than one word the words are written together and each word that follows the first is begun with an uppercase letter Rule 16 Do not use identifiers which begin with one or two underscores Rule 17 A name that begins with an uppercase letter is to appear directly after its prefix Table 2 3 C Coding Rules Page 7 SeaShark Detailed Design Document GENERAL DESCRIPTION SHK DDD 001 Issue 2 0 Rule Description Rule 18 A name that begins with a lowercase letter is to be separated from its prefix using an underscore Rule 19 A name is to be separated from its suffix using an underscore Rule 20 The public protected and private sections of a class are to be declared in that order the pub lic section is declared before the protected section which is declared before the private section Rule 21 No member functions are to be defined within the class definition Rule 22 Never specify public member data in a class Rule 23 A member function that does not affect the state of an object its instance variables is to be declared const Rule 24 If
82. d in quadrant4 Percentage of image classified as Sea in quadrant Percentage of image classified as Sea in quadrant2 Percentage of image classified as Sea in quadrant3 Percentage of image classified as Sea in quadrant4 Percentage of image unclassified in quadrant Page 78 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 e Percentage of image unclassified in quadrant2 e Percentage of image unclassified in quadrant3 e Percentage of image unclassified in quadrant4 e Id of classification algorithm used e MetaLine5 e Scan line number e Right Latitude e Right Longitude e Central Latitude e Central Longitude e Central Elevation e Left Latitude Left Longitude e MetaLine6 e Scan line number e Right Latitude e Right Longitude e Central Latitude e Central Longitude e Central Elevation e Left Latitude Left Longitude e MetaLine7 e Scan line number e Right Latitude e Right Longitude e Central Latitude e Central Longitude e Central Elevation e Left Latitude Left Longitude e MetaLine8 e Scan line number e Right Latitude e Right Longitude e Central Latitude e Central Longitude e Central Elevation e Left Latitude e Left Longitude e MetaLine9 e Scan line number e Right Latitude e Right Longitude e Central Latitude e Central Longitude e Central Elevation e Left Latitude e Left Longitude The executables used are Page 79 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2
83. d with an image ImageLineStatus indicates the quality of a particular image scan line ImageSummary top level class that of all objects which in some way summarises details about an image ImportCheck used to ensure files in telecom in orders are fully written before import ImportProduct abstract base class for import products ImportSeaWiFSProduct represents the SeaWiES level 0 data as presented to the SeaShark applica tion from the HRPT frame formatter functionality associated with the Initialisation Window InitWindowCallbacks_c InteractiveCallbacks_c class encapsulating callback functions for the Initialisation Window class encapsulating callback functions for the Interactive Control Window of the GUI InteractiveControls_c functionality associated with the Interactive Control Window MainCallbacks_c InterSlope contains value pairs and provides manipulation functions IntervalCounter counter which maintains state within a file IRData contains parameters and tables for calibration of AVHRR IR bands LandSeaMask represents the the land sea mask data that is generated during the SeaShark product processing chain from the Digital Chart of the World LatLongToLine converts latitude longitude to start stop line number Level0Product represents level 0 products of either AVHRR or SeaWiFS Levell ArchiveImage represents level 1 images in archive format Line represents lines MainWi
84. describes the processing activities that have taken place at an acquisition station There are three types of report e an acquisition and archiving report which describes the products which have been acquired and archived e a distribution report which describes the products which have been distributed to users e a media report which details the media which have been used All report types have the same basic structure which consists of two header lines followed by a variable number of report lines The content of the lines varies according to the report type The formats of the lines are now described The first header line identifies the type of report and is formatted as shown in Table 5 28 sites Start Stop Size in No Name Short Description P Type byte byte bytes 1 SeaShark_strin Identifies the reportasa 1 8 8 ASCII SeaShark g SeaShark report blank 9 9 1 2 type Identifies the report type 10 35 26 ASCII e g Distribution blank 36 36 1 3 report_string Identifies a report 37 42 6 ASCII Report blank 43 43 1 endline 44 44 1 Table 5 28 Format of the First Header Line of a Report The second header line identifies the period for which the report is valid and is formatted as shown in Table 5 29 heen Start Sto Size in No Name Short Description P Type byte byte bytes 1 Title_text 1 14 14 ASCII Report betweenv blank 15 15 2 start_date_ s
85. divided into directories labelled using the following fields from the Order destination Page 31 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 code order code suborder number see 36 Within the order directory each of the files are named using the following pattern AASSSSSS EEE where AA acquisition station SSSSSS sequence number and EEE extension sta The above pathnames can be changed by editing the configuration file SeaShark automatically moves files from one directory to another at the appropriate time in the processing chain 3 14 4 Errors There are several different types of error non fatal errors which are reported via the shell win dow that SeaShark is running in and fatal errors or warnings which are reported by the use of dialogue boxes The following list describes the actions which SeaShark can take when an order error occurs 1 Reject and delete the order 2 Reject the order and write a status file 3 Place the order in an error state 4 Ignore the error and use a default where appropriate 5 Move the order to the failed order directory 6 Write an error message to the shell 7 Write a simple error notification message in the Main window 8 Show an info warning error dialogue box 9 Crop the image to fit the pass height The following table shows possible errors the point in the processing chain at which the error is detected and the action that SeaShark wi
86. e in gt Name Short Description P Type Times byte byte bytes Latitude Longitude of the Grid Point 4 int 1 180 to 180 degrees Longitude Latitude of the Grid Point 4 int 1 90 to 90 degrees Sun_Azim Sun azimuth angle at the grid 4 int 1 point 180 to 180 degrees Sun_Elev Sun elevation angle at the grid 4 int 1 point 90 to 90 degrees Sat_Azim Satellite azimuth angle at the grid 4 int 1 point 180 to 180 degrees 6 Sat_Elev Satellite elevation angle at the 4 int 1 grid point 90 to 90 degrees Table 5 11 Format of the Grid Point Values structure All values are stored in units of 1 1000th of a degree 5 4 3 Land Sea Mask File The Land Sea Mask file contains a binary image with the same dimensions as the product s image The pixels of this image hold classification e g land or sea coastline etc information about the equivalent pixel in the product image The land sea mask file is made up of a series of land sea mask records The format of the Land Sea Mask Record is shown in Table 5 12 Page 49 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 bate Size in i Short Description Type Times bytes Copy of the scan line flag from Binary 1 the product s image unsigned short Day of year of the line unsigned 1 short Millisec Millisecond since midnight of unsigned 1 onds the line int Classificati Classification informati
87. e orbit to the exact time of a particular scan line and determine the satellite s position This is accomplished using ESRIN provided orbit propagation algorithm If GPS navigation has been selected only available for SeaWiFS SeaShark uses the GPS data in the image file GPS data is read out of the State Of Heath telemetry in the HRPT see 38 SeaShark searches for the GPS data set time stamped as nearest to the image scan line The position and velocity vectors found are propagated as above to determine the satellite position at the time of the current grid line If SeaShark detects an error in the GPS data for example if the satellite position suddenly changes beyond a set limit these limits are set in the SeaShark Page 74 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 configuration file SeaShark will disregard the value and interpolate from previous values When no valid GPS data can be found an error is reported to the user The satellite s attitude is initially assumed to be nominal i e no attitude offsets from nadir view This may be modified with regard to the roll angle during the Coastline Adjust step see section 6 2 5 If GPS navigation has been selected only available for SeaWiFS then the derived attitude information provided in the State of Health telemetry together with the GPS data is used see 38 Since the attitude is updated every 2 seconds the attitude change rates are not u
88. ecial order Port Rec 16 Do not write code which is dependent on the lifetime of a temporary object Port Rec 17 Avoid using shift operations instead of arithmetic operations Port Rec 18 Avoid pointer arithmetic Table 2 5 C Coding Portability Recommendations 2 5 Software Development Tools The following software development tools and packages are used Sun WorkShop Visual will be used to develop the graphical user interface the bundled GUI builder is based on XDesigner Sun Visual Workshop tools will be used for compilation and debugging Rogue Wave Tools h will be used wherever possible to provide standard re usable classes RogueWave Maths h and LApack h will be used to provide matrix classes for the nav igation procedure Proj will be used to provide general image projection functions Xpm will be used for handing the icons of the graphical user interface IDL will be used for testing XV will be used to provide GIF image handling functions and for testing RCS will be used for configuration control purposes A full description of tools is given in the Software Transfer Document 11 Page 11 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 3 PHYSICAL DESIGN 3 1 Introduction This section describes how SeaShark is divided into physical design elements and how those elements communicate with each other 3 2 The Process Model The physical design of SeaShark is
89. ectories and libraries from the src directory of a SeaShark installation Used before CreateInstallTape Table 7 3 Scripts used by SeaShark 7 4 Processes 7 4 1 Media Handler The media handler is an event driven process spawned by the graphical user interface GUI process All archive and distribution requests are sent via socket connection to the media han dler Each I O request is in the form of a list of products Other requests include status direc tory and device manipulation requests such as eject media 7 4 1 1 Process Execution STEP 1 Initialisation During initialisation the process reads a configuration file called Media Handler cfg and connects to the predefined GUI process socket For each device specified in the configuration file a device handler process is initialised Once communication has been Page 104 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 established with these processes the media handler sleeps awaiting a message from the GUI Process STEP 2 Request Handling When a message is received on the socket from the GUI process the media handler parses the requests and sends the appropriate message to the device handler For each connection the media handler maintains a queue of requests When requests are com pleted they are removed from the queue and their status is returned to the GUI STEP 3 Termination If the GUI is shut down a message is received to exit During t
90. ed information such as the image s colour table Histogram_c HistogramCallbacks_c represents histograms of any parameterised type class encapsulating callback functions for the Histogram Window HistogramEntry used internally by Histogram HistogramWindow_c functionality associated with the Histogram Window of the GUI Histogram WindowData represents the internal state of the Histogram Window HolbenData contains the Holben values for AVHRR leve 2 processing HolbenTable contains the set of Holben data for a given sensor HRPTxxxx describe different parts of HRPT format files The classes allow the reading and writing of sections of a n HRPT scan line The classes also allow access to individual fields in a section Details of the HRPT formats can be found in section 5 HRPT_types abstract base class for classes representing different HRPT formats HRPTA uxilliarySync represents the auxilliary sync field which is at the end of HRPT minor frames within a HRPT image HRPTFrameSync represents the frame sync field which is at the start of HRPT minor frames HRPTImage represents common aspects of all HRPT images Handles generic I O and access to non instrument specific aspects of HRPT images HRPTImageSummary represents the first quality check information and other summary informa tion about an HRPT file which is used though the SeaShark processing chain HRPTLineStatus denotes the status of a line in a H
91. ensure that e related data types are kept together e different data types are kept apart e access to data is efficient Since SeaShark uses a wide variety of different data types a directory hierarchy of several lev els is employed For clarity this is reflected in the description below First the top level of the hierarchy is described then lower levels are described separately The descriptions are of the standard SeaShark system as provided on the installation tape It should be noted however that the directory structure is configurable it is possible by editing configuration files to change the structure to reflect particular circumstances at an acquisition station SeaShark finds its home directory from the environment variable SEASHARKHOME and the primary config uration file from the environment variable SEASHARKCONFIGFILE A full description of SeaShark directory and file naming conventions appears in the Software User Manual 10 3 7 1 Top Level Directory Structure At the top level SeaShark is divided into a number of directories as illustrated in Figure 3 4 Page 19 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 O SeaShark SeaDAS Xpm bin config data doc help include install lib qasw src verify Figure 3 4 Top Level Directory Structure The contents of the directories are described in Table 3 5 Directory Content OceanColourF77 SeaWiFS Level 2 Fortran code PROJ 4 source
92. es 53 BA A a A Aa GES 55 5 4 9 Acquisition Details File sssesseessesseeeseeeesseesseesseesseresseeessressersseesseresseee 55 5 410 Orbit Data Fil li es 55 SA Archive Tape Index Ple ida 55 9 9 Fast Delivery Pro dad to Ea dde 56 Deel PIAS S PUG occ ic Sos snc cehces E AE E A E EE 56 3 32 Description File iii tai 56 5 6 Level 1 Distribution Product aj ccnien vast dd 58 5 0 L IMAGE Pile esca 58 502 LE AIDE RP a o N E Aa 58 5 6 3 NUEL VDE Ple ui ara 58 A RAR File iati ieri o A AOS 58 Nid VDE FIle ona edad a a aig uc ddkedee ds Nine nandvas ans aaa geen east aaats 58 5 6 6 Distribution Tape Index Pl Aia na anios 58 3 0 7 Order Status Tle inuit idad scada 58 560 0 Order MIG A E e A 59 5 1 Level 2 Distribution Prod 61 A E E A aE 62 Os 2 PA PP R F e E E 62 31 3 NULL VDE File saladas 62 A O 62 A avian eerawenten nara anaes 62 page vi SeaShark Detailed Design Document Table of contents SHK DDD 001 Issue 2 0 5 7 6 Distribution Tape Index File o sisacsessccisstececesasessscsvensdcasascceeteacesedetaunsccueae 62 5 1T Order Status HIG estes tothe se Seek etna dias Baas tada 63 5 7 8 Ord r TNS eft So o dt e Osh ne ES 63 SKE 0100 O 63 5 9 Configuration File Format aos ai ren 66 3 10 Log File Fora tirano nei a E T EE RE eii 67 ILEMEDA FORMATS sneinen tiated gpg ets n a n nna ean 68 IA Archive Tape ii 68 3 112 Distribution Tape dd a en S ota iii 70 Section 6 PROCESSING STEPS esseseesessessosseseesossesosso
93. es in a Level 1 Archive Product c temporary file exists only on disk when the product is first generated SeaWiFS only 5 4 1 Imagery File The SeaWiFS imagery file contains a number of Image Data records each of which is format ted as described in Table 5 4 Name Short Description Type Times Scan_Line_F Scan line flag unsigned 1 lagl short Scan_Line_ Scan line day Day of Year unsigned 1 Day short Scan_Line_T Scan line time millisecs of day unsigned 2 ime short blanks ASCII 1 Spacecraft_I Spacecraft Identifier 2 x 16 bit unsigned 2 D words short 6 Spacecraft_T Spacecraft time tag 4 x 16 bit 14 21 unsigned 4 ime_Tag words short Table 5 4 Format of the SeaWiFS Level 1 Image Data Record Page 44 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 bia Start Stop Size in Short Description sere Why ee Type Times 7 Spacecraft_S Spacecraft state of health teleme 796 7715 byte 715 OH try 775 x 8 bit words Intstrument_ SeaWiFS instrument and ancil 884 88 unsigned 44 Telemetry lary telemetry 44 x 16 bit short words 900 16 916 16 932 16 Gain_TDI Gain and TDI for the 8 bands unsigned 8 short Start_Synch_ Start synch pixel for the 8 bands unsigned 8 Pixel short Dark_Restor Dark restore pixels for the 8 unsigned 8 e_Pixel bands short Image_Data Pixel interleaved SeaWiFS data Structure 1285 1285 pixels per scan line Table
94. essing of lists of orders The filters at the top of the window allow the operator to view orders which satisfy the selected criteria the display is updated automatically Each line in the list represents an order and shows the current status of the order s processing The information shown is e Product the identifier for the reference product associated with the order e Order the unique identifier for the order ESA order code and suborder number combina tion e Level the stage to which the order has been processed The possible levels are e used before retrieval and after distribution e L1 Arch used by retrieved orders e Order type e g L1B L2A L2B LFD1 SFD1 used by generated product e Status the current processing state for the order The possible states are e Error something went wrong with the last step e Ready the order is ready for the next processing stage e Batch the order is ready for the next batch job e Queued the order will undergo processing when the immediate queue empties e Active the order is undergoing processing e To defines the next stage in the processing chain The possible stages are e Retrieve ensure the reference product is on the system e Order type Processing generate the ordered product e Order type Distribute write the generated products to the distribution medium e Delete remove the generated products from the system e Customer the
95. face process The User Interface reads the con figuration file to find the location of the processes to start and then spawns each one as a child process The User Interface then attempts to connect to each child by a standard socket If the socket is still active a socket reuse facility is tried to initiate the connection Once each connec tion has been made the User Interface allows operator interaction Spawning a process is done by the Unix specific fork and execv commands If the processes cannot be spawned or communications cannot be made the User Interface cleans up and exits A media handler process one for each different type of device controls any device access by queuing requests and allowing the interface to continue without having to process a continual stream of messages from the device handlers The processor process communicates with the interface to get instructions as to the processing steps required As each request arrives the processor spawns independent executables to per form the processing This allows easy maintenance as each executable can be changed inde pendently of SeaShark and command line access to the processing steps Each process step that the processor spawns runs to completion without giving control back to the processor On completion of each process step a log file is written detailing its results Every feasible parameter is passed on the command line to these processing steps No other means of com
96. ficients FDPCodes represents the special pixel codes used in FDP image data FDPConsts encapsulates constant definitions for FDPs FDPData represents FDP image data FDPProjection encapsulates FDP projection choice FieldPos represents a field within an order file GenImage used internally by TransformCoefficients abstract base class for images without bit unpacking Table 7 2 Classes Used by SeaShark SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 Class Name GULxxxx Description contain global classes used by SeaShark They are declared in the interface and are all used internally by SeaSharkGlobals This guarantees their order of construction and destruction GUL Display low level Display Window functionality GUICatalogue provides global access to the catalogue store GUIImportMonitor provides global access to functionalty to monitor product import GUIImportTimer provides the timer used for updating the interface and checking directories such as the import directory GUlMessageStore provides message handling facilities used for socket communication GUIObjectStore provides object handling facilities GUIReports provides report handling facilities GUITaskMonitor provides global access to functionality to monitor tasks Giflmage represents an image in standard GIF format The class provides functions for reading and writing an image and for accessing associat
97. grity and then rerunning the processing from an appropriate step This section describes a number of possible errors and the action needed to recover from them e Catastrophic system crash such as disc failure unrelated to the SeaShark software If this happens then the site system administrator will have to fix the fault and maybe place the data back on to the system as it was at the last system backup When access is gained to the system the SeaShark interface should be run Any log files or processing files will be removed and the system returned to a state where all processing can continue At times the system may find it has reached a state where there are two products of the same name on the system SeaShark will detect this and query the operator to remove the product Killing of processes If the interface process is killed then each of the sub processes will exit because each socket will detect the fact that it is not possible to communicate to the inter face and the process will finish what it is doing and exit On restarting SeaShark the system will read the last status of the system and restart this may mean that the last few operations may be lost If any of the other processes die the system will complain when any requests are sent to the dead process It is up to the operator to exit SeaShark and restart it It will be possible to continue with remaining processes 3 13 Tasks 3 13 1 Description The task is an important concept
98. h memory to access the Memory problems DCW database navigation cannot access the DCW directory The DCW directory defined in the SeaShark cfg parameter dcw_database_directory does not exist any stage Tasks are incompatible for multiple The multiply selected tasks are not at selection the same stage of processing navigation cannot create land sea mask file The product directory had been deleted or is read only Level 1 cannot create such a large quicklook The size of the quicklook is too large Table 3 14 Processing Errors Page 34 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 Stage of hee Bee Error text Description or error processing Level 1 Error in given sampling factor The sampling factor given in the Sea Shark cfg in the parameter quicklook_ lt sen sor gt _sampling factor is incorrect Level 1 Sampling factor must be greater than The sampling factor given in the Sea Zero Shark cfg in the parameter quicklook_ lt sen sor gt _sampling factor is incorrect Table 3 14 Processing Errors Page 35 SeaShark Detailed Design Document PROCESSING INTERFACE SHK DDD 001 Issue 2 0 4 PROCESSING INTERFACE This section defines how SeaShark executes processing tasks Some are automatic others require operator intervention 4 1 Archive Processing 4 1 1 Polling The Import Directories SeaShark makes use of timers to trigger events On every timer expiry default 10 sec
99. hark s main task is to generate products The generated products are stored under this directory A number of sub directories are used to distinguish products from different sen sors and products at different stages of processing reports SeaShark regularly generates a number of reports detailing the processing activities for transmission to the central ESRIN site The reports are stored here internally tapes SeaShark writes a index file for all distribution and archive tapes tasks SeaShark monitors the processing of products and their current state Information relating to this monitoring function is stored in this directory telecom in SeaShark exchanges information with several external systems by file transfer over a net work Files to be received from an external system are placed in this directory from where they can be read by SeaShark telecom out SeaShark exchanges information with several external systems by file transfer over a net work Files to be sent to an external system are placed in this directory telecom prepare SeaShark exchanges information with several external systems by file transfer over a net work Files can be prepared in this directory Table 3 6 Content of the data Directory top level 3 7 3 1 Structure of the catalogue Directory The catalogue directory is divided into sub directories first by sensor then by year and finally by month so that all catalogue entries from a given sensor w
100. he exit phase the current request on each of the devices is completed and each queue is saved The same actions are taken if the socket connection to the GUI is broken 7 4 1 2 Requests Each request will contain a device name a request type which consists of the standard device operations such as read write or retrieve status and a list of products Typical requests will be processed and split into lists of files to be send to the device handlers Socket messages will be sent in packets which will be handled by a Packet class The structure Description J Request ID Device Device Request Request Number of Product Name Type Argument Products 20 2 50 Table 7 4 Request Structure of the request is shown in Table 7 4 and a brief description of the fields follows e Request ID is a unique number for each request structure which is sent on each socket Device Type can be one of the following supported devices e Optical Disk e Exabyte e Device Name is the alias given to the device from the configuration file From this alias the media handler can obtain the device special file and the number of products that can be placed on the device e Request Type details the type of work the device is to undertake e O Reset e Read e 2 Write e 3 Get Status e 4 Get Directory e 5 Eject e 6 Stop e 7 Rewind e 8 Forward e 9 Forward Skip File e 10 Backward Skip File
101. he table for the radiance value and hence retrieves the corre sponding brightness temperature To speed the process the starting point in the search is set to the location which held the results for the previous pixel When radiance corrections are not available a brightness temperature correction is made Tables of these corrections are available from NOAA The table consists of a set of corrections which are proportional to the scene temperature and the internal target temperature SeaShark looks up the correction using the pixel s temperature and PRT value and linearly interpolates within the table to find the correct value If the scene temperature or the PRT temperature is outside the range of the table the closest value in the table is used Values are not extrapolated The final results are scaled to fit into 16 bit words and written to the SHARP IMAGE file The difference in brightness temperatures calculated by SeaShark and it s predecessor SHARK are in the order of 0 1K For further information refer to the Sharp Level 2 User Guide NOAA Technical Memorandum 107 Appendix B and subsequent amendments 39 6 13 NOAA KEM and the AVHRR 3 type instrument SeaShark supports the new AVHRR 3 instrument which will be flown on the NOAA K L and M satellites AVHRR 3 has a new 6th channel in the near IR at 1 6um This will be referred to as 3A and will replace the 3B channel during the daylight part of the orbit Another new fea ture of the
102. he use of numeric values in code use symbolic values instead Rule 38 Variables are to be declared with the smallest possible scope Rule 39 Each variable is to be declared in a separate declaration statement Rule 40 Every variable that is declared is to be given a value before it is used Rule 41 If possible always use initialization instead of assignment Rule 42 Do not compare a pointer to NULL or assign NULL to a pointer use O instead Rule 43 Never use explicit type conversions casts Rule 44 Do not write code which depends on functions that use implicit type conversions Rule 45 Never convert pointers to objects of a derived class to pointers to objects of a virtual base class Rule 46 Never convert a const to a non const Rule 47 The code following a case label must always be terminated by a break statement Rule 48 switch statement must always contain a default branch which handles unexpected cases Rule 49 Never use goto Rule 50 Do not use malloc realloc or freed Rule 51 Always provide empty brackets for delete when deallocating arrays Table 2 3 C Coding Rules Page 8 SeaShark Detailed Design Document GENERAL DESCRIPTION SHK DDD 001 Issue 2 0 Rec Description Rec 1 Optimize code only if you know that you have a performance problem Think twice before you begin Rec 2 If you use a C compiler that is based on Cfront always compile with the w flag set to elim
103. heduling of the task none immediate or batch _subject_type _subject_id Type of task order product reference product etc Either the product or order id _product_id _state Either the product or reference product id The state of the task i e uninitialised processing etc _process_type _type_of_product Current or next process to happen Describes processing type e g LIA L1B FDP etc _ optical _x_offset _y_offset Name of optical order Offset values used for Coastline Adjust _last_x_ offset _last_y_offset _process_steps Offset values used for the previous Coastline Adjust Work that has been done on the task _import_type _default_optical Type of import HRPT Level0 Archive or Levell Default string for _optical Table 3 10 Task Form data structure The TaskForm data members _process_steps and _process_type are used to control task processing For an inactive task _process_type specifies the next step in the processing sequence The mask _process_steps records each step of the processing sequence that the task has undergone or that has been selected for future processing This parameter reflects the dis position of toggle buttons on the task form window The function update_task is used to update the Task Pool when a task changes The disk copy of the task is also updated if _dirty_bit is set Processing is initiated by placing the task on one of
104. hich relate to the same year and month are stored together Each catalogue entry is stored in a separate file 3 7 3 2 Structure of the products Directory SeaShark generates products using the data received from two different sensors e the SeaWiFS sensor on board the SeaStar satellite the AVHRR sensor on board the NOAA series of satellites The products from each sensor are kept separate by dividing the products directory into AVHRR and SeaWiFS sub directories For both sensors SeaShark products are generated by a processing chain For each step in the chain SeaShark maintains a directory into which are placed all products that have undergone that processing step As the steps of the chain are exe cuted the product is moved into the appropriate directory The directories used by SeaShark to store products as they progress through the processing chain are listed in Table 3 7 Page 22 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 Directory Content Import Raw HRPT Level 0 or Level 1 data sets Level0 Products which have been imported quality checked and formatted to Level 0 Navigated Products which have been navigated Levell Products which have been processed to level 1 archive format FDP Products which are in fast delivery format L1Dist Products which are in level 1 distribution format Level2 products which are in level 2 distribution format Table 3 7 Content of the data D
105. his is not the case The data members of the TaskPool are shown in Table 3 8 New tasks are created when prod ucts are imported or retrieved and when new orders are generated Tasks are deleted when products and orders are deleted or removed Variable Description _avhrr_task_list Linked list of AVHRR tasks _seawifs_task_list Linked list of SeaWiFS tasks _global_task_id Counter for updating task id _task_type_filter Filters used for task list display _task_status_filter _scheduling_filter _process_status_filter _source_media_filter Table 3 8 Task Pool data structure Page 27 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 3 13 4 Individual Tasks Each task has an instance of a Task class which in turn has an associated TaskForm instance It is the TaskForm data that is written to disk The data members of the Task class are shown in Table 3 9 and data members of the TaskForm class are shown in Table 3 10 Variable Description _task_ form TaskForm instance _valid Boolean to flag valid invalid tasks _task_id Task id number Table 3 9 Task data structure Variable Description _dirty_bit TRUE if structure needs to be saved FALSE otherwise _prepared_telecom _tmp_suffix Indicates that files have been copied to telecom_prepare Suffix to use for temporary files _sensor_info _schedule_state Describes the sensor for this task SensorInfo instance The sc
106. hive and CEOS distribution products Not currently used but will be required in the future Station represents an aquisition station StringDB associates a string key with an object for use with an object database SunEarthGeometry represents the geometry of the Sun and the Earth at a given time SunRasterImage SW_FrameFormatted SW_Raw10BitHRPT represents a rasterfile for quicklook images represents a SeaWiFS frame formatted HRPT image Task TaskCallbacks_c TaskForm TaskFormCallbacks_c X callback functions for the Task Window of the GUI stores detailed information for a given task TaskFormWindow_c TaskPool represents a SeaWiFS 10 bit formatted HRPT image represents the task concept within SeaShark X callback functions for the Task Form Window of the GUI functionality associated with the Task Form Window of the GUI stores the list of tasks on the SeaShark system grouped by sensor abstract base class for task queues TextWindow_c TaskQueueStore Task Window_c functionality associated with the Task Window of the GUI TBUS The TBUSxxxx classes describe parts of a TBUS message which provides orbital information for NOAA satellites A TBUS message is divided into a number of parts of which the Part 4 is relevant to SeaShark The Part 4 con tains a number of lines The classes allow the reading and writing of the lines from and to a file They also allow access to individual fields in a line
107. igure A 5 TransformCoefficients hierarchy Page A 2 SHK DDD 001 Issue 2 0 SeaShark Detailed Design Document JND Odd 22701048 DINDOAdz IRMA danys DRDO EL IP RAM DOS Lm LL Pnpolgojenc 34 HAY PNPOLO AAR SY MEAS 20049 1190014 FAN janpold ha7 416295 Pripolg deus Prpa LISE PNpolgo aney PNpOdd jaral PnposgsO7 PnpolAsaaljaqysey pnpolg4ejds1g PnpoJg lpalIg Pn pou od ys 4 Meas PA pedo PNpOlVod Wy AHH AY pnpoly Figure A 6 Product hierarchy Page A 3 SeaShark Detailed Design Document SHK DDD 001 Issue 2 0 SeawiFSinstrTelemetry AVHRRTIPData SeawiFSStopSyncPixel SeawiFSPixelField SeawiFSDarkRestore Pixel SeawiFSStartSyncPixel SeawiFSGainAndTDI HRPTAuxiliarySyne HRPTSpacecraftiD ScanLineField HRPTTimeTag HRPTFramesync SharpCalibrationFields AVHRRCalibrationFields AVHRRSpaceData AYHRRBackScan AVHRRTelemetry Figure A 7 ScanLineField hierarchy A 2 Source Directory Structure In the following section are a selection of diagrams describing the uses of the source sub direc tories Page A 4 SeaShark Detailed Design Document SHK DDD 001 Issue 2 0 eter to Figure ontains classes containing Contains counter utility class Contains DCW utility class Contains directory utility class Refer to Figure A I Contains classes controlling messages between GUL processor and exabyte Contains utility class for two d
108. imensional bit mask Refer to Figure A 14 re Figure A 8 Sub directories of top level source directory Page A 5 SeaShark Detailed Design Document T POcesses precessing_steps Figure A 9 Sub directories of top level source directory continued SHK DDD 001 Issue 2 0 Contains classes which create new orders and handle them within SeaShark Refer to Figure A I5 Refer to Figure A IZ Refer to Figure A 13 Contains utility classes for creating and amending report files Conatins class that managers resources Contains classes that read sensor config files and Holben and IR data Contains class which allocates processes Contains class which is used to store infor mation passed between processes Contains various utility classes for exam ple reading the config files unix directory and file utilities Page A 6 SeaShark Detailed Design Document catalogue catalogue_lef cataloque_class cataloque_entry SHK DDD 001 Issue 2 0 Contain class which represents the catalogue class Contains classes Tor each of the meta lines within a catalogue file Contains classes which create and maintain the catalogue batch file Figure A 10 Catalogue sub directories cleanup display glebals interface kernel utility windows Contains utility class which provides con sistent interface to clean up files
109. irectory A product starts out in the Import directory When it has been imported and quality checked it is moved into the Level0 directory From there it undergoes navigation and is moved into the Navigated directory and so on Refer to Figure 3 2 The directory structure of Table 3 7 is not quite complete Within each of the directories of Table 3 7 the files from each product are stored in a sub directory labelled with the Product Id 3 7 3 3 Structure of the orbit_data Directory There are two orbit_data types e TBUS messages e TLE Two Line Element sets The orbit_data directory is divided into sub directories first by orbit_data type TBUS amp TLE then by year and finally by month so that all orbit data messages of a given type which relate to the same year and month are stored together Each orbit_data message is stored in a separate file 3 7 3 4 Structure of the telecom in Directory The telecom directories are used for the electronic transfer of data between an acquisition sta tion and the central ESRIN site SeaShark exchanges information with several external systems by file transfer over a network Files to be received from an external system are placed in the telecom_in directory from where they can be read by SeaShark There are two sub directories orders into which new orders from the central ESRIN site are placed and tmp into which orders can be placed temporarily 3 7 3 5 Structure of the telecom out Director
110. k This routine searches for products used by the task Return values indicate whether the product is on disk and if the product is referenced by an order Table 3 12 Selected task member functions 3 13 7 Task example Consider a task which is to undergo Navigation processing When the task has been selected from the task list the task form window is built using AppearTaskForm The toggle buttons are set using the _process_steps and _process_type values In this example no toggle buttons are shown as being depressed Now press the Navigation button in the task form window The function ProcessStepChanged checks that the button configuration is valid before setting the button display and tests the _process_type bit in the _process_steps mask to confirm that the next process to run matches the button selection A confirm window is then displayed to allow processing to begin When Immediate is pressed the task s schedule state is set to Immediate and the task state to Waiting i e Queued Using update_task the task is updated in memory and on disk Finally the task is placed on the process immediate queue On the next SeaShark timer event the queue handler function service will poll the process immediate queue If the navigation task is the next task that is in the Waiting state it will be processed by do_service This function builds a token and passes it to processor_handler It also sets the task state to Processing and upd
111. l orders the order file is placed directly into the SEASHARKDATA telecom in orders directory 4 2 10 2 Order Form Window In the discussion so far orders have arrived via network and have been automatically imported into the system In some circumstances for example when network communication with ESRIN is not possible it may be necessary to manually enter orders into the system This can be done using the same order form which was described above for viewing full order details From the order form an order file is created and copied into the SEASHARKDATA tele com in orders directory This order file is then detected and used in the same way as for exter nal orders An order contains a description of the product which is required and the distribution medium needed to disseminate it Therefore when an order arrives the process options can be set auto matically within the Task List window and the task needs no intervention apart from the initial decision between immediate or batch processing When an order is initiated its requirements are first determined and tasks created for retrieval of the desired products from the archive Each request becomes a new task and is placed within the TaskPool The calling task will interrupt itself and wait for each of the tasks to be com pleted In batch mode each of the tasks are placed on the batch queue It is assumed that in immediate mode the operator will be at his her terminal controlling the p
112. l variations should have the same semantics be used for the same purpose Rec 45 Use inline functions when they are really needed Rec 46 Minimize the number of temporary objects that are created as return values from functions or as arguments to functions Rec 47 Avoid long and complex functions Rec 48 Pointers to pointers should whenever possible be avoided Rec 49 Use a typedef to simplify program syntax when declaring function pointers Rec 50 The choice of loop construct for while or do while should depend on the specific use of the loop Rec 51 Always use unsigned for variables which cannot reasonably have negative values Rec 52 Always use inclusive lower limits and exclusive upper limits Rec 53 Avoid the use of continue Rec 54 Use break to exit a loop if this avoids the use of flags Rec 55 Do not write logical expressions of the type if test or if test when test is a pointer Rec 56 Use parentheses to clarify the order of evaluation for operators in expressions Rec 57 Avoid global data if at all possible Rec 58 Do not allocate memory and expect that someone else will deallocate it later Rec 59 Always assign a new value to a pointer that points to deallocated memory Rec 60 Make sure that fault handling is done so that the transfer to exception handling when this is available in C may be easily made Rec 61 Check the fault codes which may be received from library functions even if these functions seem OK
113. ll take in each case Error Description Stage Detected Action Invalid missing ESA Order code Import 5 6 7 Invalid missing Sub order Number Import 5 6 7 Invalid missing Satellite Id Never detected 4 Invalid missing Satellite Mission Number Never detected 4 Invalid missing Sensor Id Never detected 4 Invalid missing unknown Product Code Processing FDP 3 6 8 only Invalid missing Centre Latitude Longitude Processing 3 6 8 Invalid missing Bottom Latitude Longitude Never detected 4 Invalid missing Start Stop Date Never detected 4 Invalid missing Start Stop Time Processing 3 6 8 Invalid missing Pass Id Import 2 6 7 Table 3 13 Order errors Page 32 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 Error Description Stage Detected Action Unknown Pass Id Processing 3 6 8 Invalid missing Order Type Import 2 6 7 Invalid missing Media Type Distribution 4 6 Invalid missing Product Type Import 2 6 7 Invalid missing Priority Never detected 4 Invalid missing Product Station Never detected 4 Invalid missing Destination Code Distribution FDP 3 6 8 only Invalid missing Shipping code Never detected 4 Invalid missing Comments external order Never detected 4 Invalid missing Comments internal order Processing 3 6 8 Order already imported Import 5 6 7 Order by location size gt pass height Processing 6 9 Directory created in telecom in orders Import 4 Table
114. ludes KKKKKKKKKKKKKKKKKKKKKKKKKKKKK KKK RRR KKK KK KK KKK KK KK KKK constant definitions KKKKKKKKKKKKKKKKKKKKK RRR KKK KR KKK KKK KK KK KK type definitions KKKKKKKKKKKKKKKKKKKKKKKKK Page 6 SeaShark Detailed Design Document GENERAL DESCRIPTION SHK DDD 001 Issue 2 0 A class declarations KKKKKKKKKKKKKKKKKKKKKKK RRR KKK KK KKK KK KK KK KK variable definitions KKKKKKKKKKKKKKKKKKKKK function declarations function definitions Before being placed in the devsw subdirectory the module header will be updated with the key words necessary to bring the module under configuration control by the RCS package Debug statements will be used to print information which is useful in debugging A VEGA standard DBG macro will be used which can be turned on or off when compiling the system Each module will be built using the Unix make facility Recursive make files will be used C specific programming standards are listed in the table below They are taken from 8 and 32 They are divided into three types rules Rule which are mandatory recommendations Rec which are suggested and portability recommendations Port Rec which are specific recommendations aimed at ensuring portable code Rule Description Rule 0 Every time a rule is broken this must be clearly documented Rule 1 Include files in C always have the file name extension Rule 2 Implementation files in C alwa
115. mediate queue batch queue or none GetTaskState This is one of Uninitialised Waiting Processing Archiving Retrieving Dis tributing or Error GetProcessType This indicates the next or current process The type for Level2 processing is TypeLevel2 and the specific processing is indicated by GetTypeOfProduct GetTypeOfProduct This is one of L1Arc L1ADist L1BDist L2ADist L2B Dist FDPDist L2CDist There are also Boolean functions available for individual product types eg IsL1A IsFDP GetTypeOfProduct There are a number of functions available that return task parameters as text String strings These are mainly used for display purposes GetProcessSteps This is closely linked to GetTypeOfProduct The process_steps mask consists of all the process_type values for a task OR d together GetName This returns a string containing the product or order ID getProductDirectory This returns where the product data required for processing the next step is stored on the system getCurrentProductDi This returns where the product files are currently stored on the system or an rectory error if the product files have not yet been created next_task Create a new task with the next global task id update_task Update a task in memory and on disk get_task Searches for a task within the task pool and returns it if found remove_task Searches for a task within the task pool and removes it if found product_on_dis
116. mport directory The IMAGE_HRPT and AQTIM DAT files remain unchanged After successful import the IMAGE_HRPT and AQTIM DAT files are removed from the import directory Executables used are e SeaShark e Import_AVHRR_Product AVHRR e Import_SeaWiFS_ Product SeaWiFS 6 1 2 Level 0 import A product that is already at level 0 can be imported into SeaShark This is the case after stitch ing two products together The import process is started by a catalogue iuf file with associated AQTIM DAT for AVHRR and image lla being placed in a sub directory Refer to 9 for more detailed informa tion Files copied e catalogue iuf e AQTIM DAT for AVHRR e image lla Page 73 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 Executables use are e SeaShark Similar procedures apply to import of Level 1 archive products from the Archive next step Archive and Levell reference product sub directories 6 2 The Navigation Process A large number of the processing steps require SeaShark to calculate the geographical position of any pixels in an image To offset this processing burden most of these calculations are done before the data is required The navigation process can be roughly broken down into three distinct stages 1 locating the satellite s position attitude and viewing geometry 2 generating the navigation grid 3 interpolating within the grid to find the pixel position of a given geogra
117. mport process is started by an AQTIM DAT file with associated HRPT image file being placed in a sub directory 2 Identification of the HRPT format The mechanism is as follows e For AVHRR in turn assume the input image is in one of the possible formats e For SeaWIFS format identification relies on the invariant CWIF characters at the start of a Frame Formatted image if these are not present then SeaShark assumes it is either a raw 10 bit HRPT or an HMF HRPT image depending on the setting of a flag in SeaShark cfg use_SeaWiFS_HMP Search for the first block of scan lines in the image with coherent time tags This block must be greater in length than the coherent block length defined in Sea Shark cfg import_coherent_block_length The correct format of the image will return the lowest starting line number of this block Data prior to the start of this first coherent block will be discarded as noisy data 3 The first quality check of the image This looks for bad or missing lines in the image by searching for incoherencies in the time tags of the HRPT records 4 The output image is automatically split if one of the following 3 conditions are true The input HRPT image spans midnight UTC A sequence of bad or missing lines are found in the image whose total length exceeds the product break length defined in SeaShark cfg import_product_break_length For SeaWiFS the instrument tilt state changes A new tilt sta
118. munication exists between these processes to make development of new process ing steps a simple exercise 3 10 System Close Down When the User Interface is closed every open socket connection is sent a message to tell it to close down This allows every process to finish its current work and exit in a graceful manner 3 11 Controlled Termination of Processes Under certain circumstances an operator may wish to terminate a process before its natural completion SeaShark handles this situation carefully to prevent the operator having to restart SeaShark It ensures that the integrity of queues and process status flags are kept System resources such as file descriptors and any communication resources are relinquished correctly to avoid problems of free resources later Our aim is to separate the processing steps from the main processor process to allow it to be terminated However we do not want to make it difficult to return the status each processing step A solution to this problem is to trap an interrupt which can be generated by the unix system command kill The kill command would be executed with the process id of the processing step This would mean that any new processes added to the system would have to trap an inter rupt clean up their system resources write the log file to indicate what happened and exit A second and probably cleaner solution is to kill the child process and monitor the return status from the processor Sp
119. n erate AVHRR and SeaWIFS Quicklooks Figure A 12 Processing_Steps sub directories Page A 8 SeaShark Detailed Design Document product amp postscript filter product_class SHK DDD 001 Issue 2 0 ontains classes contains various algorithms ontains classes performming annotation perform calibration ontains classes which create SEaWiFS and sharp distribution files Contains classes which perform fdp creation tograms Contains classes which together create image data ontains classes with perform map transformation ontains classes which together perform navigation ontains classes which together perform orbit stitching Contains class which is used for postscript filter Contains classes which create both AVHRR and SeaWiFS prod ucts at various stages of process ing Figure A 13 Product sub directories Page A 9 SeaShark Detailed Design Document SHK DDD 001 Issue 2 0 Contains classes for tle gps and tbus translation code erbit_data_class Contains class used for orbit management Contains classes to handle and provide a generic interface to media devices Contains classes to handle and procide a interface to processors Figure A 15 Processes sub directories Page A 10
120. n be found using an iterative search using the affine values The search algorithm uses either the last pixel position or the middle of the image as a starting point The affine coefficients for this location are then used to calculate a better estimate of the pixel position for the geographical location When the new estimate and the current pixel position are equal the iteration stops If the process has not converged after 100 iterations the current iteration pixel position is used and the user is warned If the pixel position of a geographical location outside the image is needed an esti mate is calculated using the affine values at the corresponding edge of the image Page 76 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 6 2 4 Navigation data summary Files created are e coastline navigation e tbus AVHRR e tle SeaWiFS Files updated are e catalogue iuf For the catalogue iuf the elements filled in are MetaLine3 e Ascending Descending flag e Tilt of Satellite SeaWiFS GPS navigation flag SeaWiFS with Geographic Positioning System navigation used e tbus AVHRR TBUS or SeaWiFS TLE Executables used are e SeaShark e Get_Orbit_Data e Navigate_ AVHRR AVHRR e Navigate_SeaWiFS_GPS SeaWiFS e Navigate_SeaWiFS_TLE SeaWiFS e Extract_Coastline 6 2 5 Coastline adjust The Coastline which was obtained in the Navigation stage is visually displayed to the user and can be ma
121. ncorporating some of the constants into A and B which are constants throughout the image Both the slope and intercept values are con figurable and set in the detailed sensor configuration file Page 83 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 6 11 2 Odd numbered satellites The calibration of the odd numbered channels is base on the work done by Holben et al This method more reliably compensates for the degradation of channels one and two over time When holben coefficients are available calibration proceeds using these The raw counts are converted to equivalent Reflectance using 2 a P eo fe j 1 2 r 1 c 100 x mx d AON Feces OO fori 1 where E Equivalent solar irradiance a Calibration coefficient for band i CNo deep space digital count for band i and other terms are defined above 6 12 Calibration of Thermal AVHRR channels Extraction of in flight calibration data The in flight calibration data for the IR channels consists of a space count an internal calibra tion target count and three PRT temperatures for each scan line The PRT temperatures are derived from 4 PRTs embedded in the sensor housing The values from these sensors are time multiplexed so for five consecutive scan lines one reads a sync PRT1 PRT2 PRT3 PRT4 and then the pattern repeats Three readings from each PRT are recorded and a majority count rule is used to decide the count used for the current
122. nd to copy files from the following directories install bin help qasw data DCW data orbit_data data ancillary config verify and if source code is required lib src include Makefile SeaDAS OceanColourF77 PROJ 4 Xpm and doc 7 6 3 Install Unpacks a SeaShark installation tape to the location pointed to by the SEASHARKHOME environment variable Checks that SEASHARKHOME is defined and prompts the user for confirmation that this and TAPE are set correctly Runs SeaSharkBuildDir and SeaShark BuildComms Prompts the user for permission to append the cshrc SeaShark file to the existing HOME cshre file Rewinds the tape and extracts the files 7 6 4 SeaSharkBuildComms Creates communication files for SeaShark i e sock files which define unique socket numbers for SeaShark to use for communication with spawned processes like exabyte and processor 7 6 5 SeaSharkBuildDir Creates the complete directory structure required to contain all the files used by SeaShark Checks that the SEASHARKHOME environment variable is defined and creates the directory structure at the location pointed to by SEASHARKHOME 7 6 6 TidySeaShark Removes unwanted files used prior to the creation of an installation tape Checks that the SEASHARKHOME environment variable is defined and prompts the user for confirmation Removes testfn directories RCS directories Templates DB directories object files o library files a and hidden make files
123. ndow_c X callback functions for the Main Window of the GUI functionality associated with the Main Window of the GUI MediaToolCallbacks_c ManditoryCMDArg used internally by CmdArg MeanOrbitalElement represents the mean orbital element information in a CEOS leader file MediaToolWindow_c MediaToolWindowData X callback functions for the Media Tool Window of the GUI functionality associated with the Media Tool Window of the GUI represents the internal state of the Media Tool window Table 7 2 Classes Used by SeaShark Page 98 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 Class Name Description Message handles low level socket messaging Message Window_c functionality associated with the Message Window of the GUL MeteorologyLoader provides functionality to load meteorology files into the SeaShark ancillary database Monitor used to call an external monitoring program MotifList functionality to handle Motif list widgets MTIO common features of all tape access NavigationData represents the navigation data within the SeaShark products i e a grid of points within a product s image for which the location sun and satellite angles are stored The also has operators to get the location or sun and satel lite for any pixel in the corresponing image NavigationDataSlicer allows buffered access to data in the navigation grid NPointInterpola
124. nncnoncnonnnnncnnnononnncccnnccinnnos 51 Table 5 18 Format of the Coastline Point structure ooooocccnnncccnoncncnoncncnonnnononcnononcnonanacinnnos 32 Table 5 19 Format of the Calibration Data Header record c oooconocccccnoccconaccnoonnnononcnonnnccnnnnos 52 Table 5 20 Format of the Calibration Data Record wi eee eeeseceececeeeeeceeeeeceeeeeenseeeesaes 52 Table 5 21 Archive Tape index file header record oooooonocccnnococonoccconncnnonancnnoncnononanonnnccnnnnos 55 Table 5 22 Archive Tape index file data record ooooocccnnncccnoncccnonaccnnncnonnnnnononcnonnncnonnnaconnnos 55 Table 5 23 Format of the FDP Description File oocoonnncccnnncccnnncccnnncncnnnnnnnnnnnononcnnnnnacinnnos 56 Table 5 24 Order status file data Record A o tias 58 Table 5 25 Order file data R cord As 59 Table 5 26 Tape distribution index file header Record ooooocccnnncccnnoccconaccnooncnononanonananinnnos 62 Table 5 27 Tape distribution index file data record oooooonnccnnnccnoncnooncnonononononn conocio no ncnnnc cnn 62 Table 5 28 Format of the First Header Line of a Report oooooocnnccccnoccccnoncncnoncnonnncncnonaninnnos 63 Table 5 29 Format of the Second Header Line of a Report cocoococnnoccccoocccnonnnononcncnnnaninnnos 63 page ix SHK DDD 001 Issue 2 0 SeaShark Detailed Design Document List of tables SHK DDD 001 Issue 2 0 Table 5 30 Format of the Report Line of the Acquisition amp Archiving Report 64 Table 5 31 Format of the
125. nos 85 6 13 1 NOAA KEM calibration y cri eae 86 6 13 2 Changes to the IMAGE file isessicissszscsassaveascsessncsa naar cananea 86 page vii SeaShark Detailed Design Document Table of contents SHK DDD 001 Issue 2 0 6 13 3 Changes to the LEADER file uiiisisoionda opiniones dede coca resiana 88 6 14 SeaWiFS Distribution Products ii A enetnd 88 6 15 Distrib te td td od de o 88 E O eight E shield ede a 88 Section 7 COMPONEN Tripa ii 89 TL Graphical User IMG lace nilo 89 P2 Listo VO AA II ads acta teae 90 AN E E A Gee re asa 90 TL ZO AOS is 90 DiS A A ca 10 91 TS SCUIPIS its 104 TA PrOCESSES A ested net tad nt a mac nek Moers nn ited Rat ache a cade ONC ad 104 Me Media Handler A A Salas 104 TO Programs ij da escaladas 106 Teh Ingest Climatology miii aii 106 TE VEST Meteoroloji dd 106 O 106 LOL ED AAA A ds R a 106 1 6 2 CreatelnstallTape visits aiii incida arado 107 AAA a O 107 17 604 Seas Wark Build C Onan s ett 107 702 Deas Darke OG DIP coat adsl adds 107 76 6 Tidy S aS Shark ta 107 TO IESO SCA AL Re A E 8G Gee le dase 107 Appendix A SOURCE DIRECTORY STRUCTURE AND DESCRIPTION A 1 A Class interconnection mita ias A 1 A 2 Source Directory SUCHE divinidad diria atacadas A 4 page viii SeaShark Detailed Design Document List of tables List of Tables Table 2 1 Development Area Directory Structure diiaiii dc 5 Table 2 2 Directory Structure of SSEASHARKHOME ccccoccccocccoconocononncnnonncnnonncnncnncnncnnno
126. nt archive tapes AYYMMDDhhmmSST where A AJVARR or S eaWiFS YYMMDDhhmm date amp time written SS acquisition station T type X for Exabyte 3 Unused ASCII 0 4 new line char ASCII char 1012 Table 5 34 Archive Tape Label Format Note the quote characters are part of the format for text strings The Label File is identical to an empty Directory File see below A directory is the means of identifying and locating the products on the tape so that they can be retrieved When untarred from tape a Directory File has the format of Table 5 35 Short Size in No Name aye Type Description bytes 1 Header Identifies the tape as ASCII a SeaShark archive SeaSharkDIR tape 2 Archive_id Distinguishes differ ASCII of the form ent archive tapes AYYMMDDhhmmSST where A A VHRR or S eaWiFS YYMMDDhhmm date amp time written SS acquisition station T type X for Exabyte 3 Number of The number of prod ASCII products ucts on the tape up to e g 2 or 12 that point new line char ASCII char 1012 4 Directory Details of the first Structure Table 5 37 entry 1 archived product 5 Directory Details of the second Structure Table 5 37 entry 2 archived product n 3 Directory Details of the nth Var Var Var Structure Table 5 37 entry n archived product Table 5 35 Archive Tape Directory Format page 69 SeaShark Detailed Design Doc
127. nts the volume directory file of the SHARP Level and Level 2 for mats CEOS VolumeDescriptorRec a volume descriptor record of the SHARP Level 2 leader file Ref 21 CharStarArray converts strings to char s handling all the memory allocation for passing as an argv etc ClassifiedCatalogueEntry represents mandatory or optional classified catalogue entries Cleanup handles the removal of products Table 7 2 Classes Used by SeaShark Page 94 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 ConfirmCallbacks_c Class Name Description ClimatologyLoader provides functionality to load climatology files into the SeaShark ancillary database CMDArg an abstract base class which represents all the different forms of command line arguments to standalone programs CMDLineArguments reads and interprets options given to standalone programs Coastline represents coastline data extracted from the DCW that is associated with a particular SeaShark product CoastlineCoordinates represents a point s geographical lat llon and image line el co ordinates Used internally by Coastline CoastlineSegment coastline co ordinates of an edge segment Used internally by Coastline CombinedAtmosCorrn represents atmospheric correction routines ConfigListRd provides functionality to read a list of product types from a config file ConfigParamBase contains the list of valid product types used by ConfigListRd
128. nually moved so a more exact match can be obtained see 10 Files update are e coastline navigation e catalogue iuf For the catalogue iuf the element changed after successful coastline adjust are e Delta time e Delta roll The executables used are e SeaShark e Navigate_ AVHRR AVHRR e Navigate_SeaWiFS_GPS SeaWiFS Page 77 SeaShark Detailed Design Document PROCESSING STEPS e Navigate_SeaWiFS_TLE SeaWiFS e Retransform_Coastline e Set_Coastline_Offset 6 3 Levell Creates and prepares files for archiving Files created are e calibration e land_sea_mask e paper_ql ps e quicklook rs Files updated are navigation e catalogue iuf SHK DDD 001 Issue 2 0 For the catalogue iuf the elements filled after successful process to levell are e MetaLine 1 e MetaLine2 Station name Product creation date Y YMMDD Product creation time HHMMSS Product Software version id Product Configuration version id e MetaLine3 Orbit number EQCRX time EQCRX longitude e MetaLine4 Percentage of image classified as cloud cover in quadrant Percentage of image classified as cloud cover in quadrant2 Percentage of image classified as cloud cover in quadrant3 Percentage of image classified as cloud cover in quadrant4 Percentage of image classified as Land in quadrant Percentage of image classified as Land in quadrant2 Percentage of image classified as Land in quadrant3 Percentage of image classified as Lan
129. ocessing steps informing the User Interface of the success or failure of the processing cleaning up after any failed processing e Process Steps are executables which each carry out a main processing function They can be initiated by the Processor or from the command line Each executable can selectively use the parameters passed to it All Process Steps must write a log file in the standard format e Media Handler allows access to a peripheral i o device It is responsible for accepting device control requests mount unmount etc from the User Interface accepting device access requests reading write etc from the User Interface passing requests for sequential or very slow devices tape to the appropriate Device Handlers e Device Handlers communicate directly with peripheral devices which do not have their own file system and therefore cannot be mounted and treated as a normal disk One Device Han dler is spawned for each device on the system Device Handlers cope with writing multiple files thus eliminating the need for excessive communication during a read or write of one product 3 3 Inter Process Communication Processes communicate with each other in order to send and receive information In Figure 3 1 different line styles are used to distinguish different means of communication e File System Communication is represented by solid directed lines With File System Com munication one process writes inform
130. ocument Table 1 1 Definition of Terms 1 4 References The following is a list of documents with a direct bearing on the content of this report Where referenced in the text these are identified as n where n is the number in the list below 1 ESRIN Invitation To Tender AO 1 2489 HGE 93 Development of the SeaShark Soft ware System for the SeaWiFS European Data Information System SEDIS 10 June 1993 2 VEGA Group PLC Company Quality Manual QA STN 009 Current issue 3 ESA Software Engineering Standards ESA PSS 05 0 Issue 2 February 1991 4 SeaShark User Requirements Document SHK URD 002 Issue 2 13 January 1994 5 SeaShark Project Development Plan SHK PLN 006 Issue 1 21 February 1997 6 SeaShark Software Requirements Document SHK SRD 1 0 10 March 1994 7 SeaShark L2 Processor and Upgrade Software Requirements Document SHK SRD 002 30 April 1997 8 SeaShark Architectural Design Document SHK ADD 1 0 20 May 1994 9 SeaShark SeaWiFS Level 2 Processing Architectural Design Document SHK ADD 002 23 July 1997 10 SeaShark Software User Manual SHK SUM 3 0 16 December 1997 11 SeaShark Software Transfer Document SHK STD 003 18 December 1997 Page 2 SeaShark Detailed Design Document INTRODUCTION SHK DDD 001 Issue 2 0 12 13 14 15 16 17 18 19 20 21 22 23 24 34 35 36 37 ESA PSS 05 03 Issue 1 Guide to Software Req
131. on for 1 1285 Structure 1285 on_ scan line of image data or Table 5 13 or Flags 2048 20487 Table 5 12 Format of the Land Sea Mask Record a The width of the classification field is 1285 bytes for SeaWiFS and is 2048 bytes for AVHRR Start Stop Size in byte byte bytes Tipe Times No Name Short Description 1 Classifica Bit mask holding the following 1 Binary 1 tion classification 1 byte Bit 1 Coastline flag Bit 2 Political Boundary flag Bit 3 Grid Line flag Bit 4 Sea flag Bits 5 8 Free for future use Table 5 13 Format of the Classification Flags structure 5 4 4 Coastline File The Coastline File contains the coastlines and political boundaries extracted from the DCW in vector format so they can be easily overlaid on the product s image The coastline and bound ary vectors are stored in the binary format detailed in Table 5 14 Start Stop Size in No Name Short Description Type Times p byte byte bytes YP 1 No_Segs Number of coastline segments 1 4 4 int 1 in the file 2 Segment Segment of coastline or politi 5 Varia Variable Structure No_Segs cal boundary ble Table 5 15 Table 5 14 Format of the Coastline File a The size of the Segment record is variable dependent on the number of points in each segment Page 50 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 No Name No_Points
132. on processing Chain LEVEL1 ARCHIVE PRODUCT QS SS SS SS SS A Retrieve Generate Distribute COMPLETED DISTRIBUTION PRODUCT Y e Delete Figure 3 3 Distribution processing chain Processing Step Description Retrieve Located the necessary archive product The programs SeaShark and Exabyte are used Generate Creates the files needed for a distribution product Distribute Copies the distribution product files onto archive tape The program Exabyte is used Delete Deletes the distribution product files from disk Table 3 4 Steps in Distribution processing chain 3 6 1 Control of the Processing Chain SeaShark must maintain visibility and control of the processing chain so that e the available products are known to the operator e the state of any product is known to the operator e it is possible to recover from failed processing The necessary control is achieved by a combination of e Directory Structures SeaShark maintains a directory associated with each of the Steps into which are placed those data sets that have successfully undergone processing As data sets are processed successfully they are moved from one directory to another When processing is unsuccessful SeaShark retains the input data sets and deletes any half created output data sets to ensure that the system remains in the pre processing state Page 18 SeaShark Detailed Design Document PHYSICAL DES
133. onds the SEASHARKHOME data products sensor Import directories Archive HRPT Level0 and Levell are checked for new directories If a directory exists in the HRPT directory this new directory is searched to see if 1t contains an AQTIM DAT file If an AQTIM DAT file exists and an IMAGE_HRPT file is also present both files are imported into SeaShark and a Task is created which appears in the Task List window If a directory exists in one of the other Import subdirectories this new directory is searched to see if it contains a catalogue iuf file If a catalogue iuf file exists various files are imported into SeaShark and a Task is created The imported files are those required for a product processed to the level specified by the import directory name e g a levell product imported via the Level0 import directory will be imported as a level0 pre navigated product and the Task cre ated will reflect this 4 1 2 Viewing The Status Of Products The Task List window allows the operator to see the details of a product to initiate its process ing and monitor its progress It allows the processing of lists of products which are at the same stage of processing Batch processing Each line of the list represents a product and shows the current status of that product s processing The information shown is Product ID The identifier for the product Level The current processing stage for the product The following values are used e
134. onyms and abbreviations or refer to other doc uments where the definitions can be found Term Definition ADD Architectural Design Document AQTIM AcQuisition TIMe APT Automatic Picture Transmission AVHRR BPI Bits Per Inch CCT Computer Compatible Tape CEOS Committee on Earth Observation Satellites DCW Digital Chart of the World ECTN ESRIN Co ordinated TIROS Network EPOORD Earthnet Programme Office ESA European Space Agency ESRIN European Space Research INstitute FDP Fast Delivery Product GIF Graphics Interchange Format Gur IDL Interactive Data Language visualisation software Table 1 1 Definition of Terms Page 1 SeaShark Detailed Design Document INTRODUCTION SHK DDD 001 Issue 2 0 Term Definition LAC Local Area Coverage MMDD Multi Mission Data Dissemination NASA National Aeronautics and Space Administration NDVI NOAA National Oceanic and Atmospheric Administration OD Optical Disc OSC Orbital Sciences Corporation OSF Open Software Foundation PML Plymouth Marine Laboratory UK SeaWiFS _ Sea Viewing Wide Field of View Sensor SCSI Small Computer Systems Interface SHARK Station HRPT Archiving and Reprocessing Kernel SHARP Standard HRPT Archive and Request Product SIUF SeaWiFS Inventory Update Format SST Sea Surface Temperature TIROS Television and Infra Red Observation Satellite URD User Requirements Document SRD Software Requirements D
135. ory seseseseeseeseisresresseesresrrsstestsrresreseeseresressesee 21 Figure 3 6 Structure of the telecom out Directory ooooonnncccnoncccnoooccnoncncnnnnnononcnonnncccnnnaninnnos 24 Figure 5 1 Grid Dimensions structure dai di td 49 Figure 5 2 Postscript Quicklook File t c ieccsscctaetiecdeacasiegeideicdentetiaeedutawetia ng seicaadelces 54 Figure 6 1 An example of an interpolated navigation grid oooooonocccnoncccnoncnononcnononanononcnnnnnos 75 Figure 6 2 Graphical representation of an affine coefficient matrix oooccnnnnnnoninocnnannnnnnos 76 Fig re A Image Mierarchy iea E E E E E tae E a di A 1 Figure A 2 BrouwerOrbitElement hierarchy oooocnnnccnnnocccnnncccnnncccnnncnnnnnnnonnnanonnncnnnnncnnnnnos A 2 Figure A 3 CEOSGenericRecordID hierarchy ooooonocccnnoccccnncccnononononcnonnncnononcnonnncnonanacinnnos A 2 Figure A 4 QueueHandler hierarchy stas didas Ejes iras A 2 Figure A 5 TransformCoefficients hierarchy ooooonnncccnnncocnoncccnoncnononcnononnnononcnononanonnnccnnnnos A 2 Figure A 6 Product hierarchy ii a el tenets Bae an i A 3 Figure A 7 ScanLineField hierarchy ssc cusyesvesssccvnse feats tau cea cancavay aca sus ncateedsesseacsacame eos A 4 Figure A 8 Sub directories of top level source directory ooococnnocccnoncccnoncnononcnononcconanccinnnos A 5 Figure A 9 Sub directories of top level source directory CoNtiNULCd ooonooccnnoncccnonccinnnos A 6 Figure A 10 Catalogue sub directories msi airis oben A 7 Figure A 1
136. ossesessossessossesossossesossossescossesossossesossossesoosossossosossossossse 1 lel PUPOSE eE E E E E E A E E cee a es 1 A ses cee tsteuciasce toma urea hunetdos cers tenbesya dais E aeae nays ENP a NEA 1 1 3 Definitions Acronyms and Abbreviations oooooccnococooncnonononnnnnnnnonnnonnnnnncnancnnn cnn 1 ARE Terence do rl aa E Sect aans 2 ERON A E E E ET 4 Section 2 GENERAL DESCRIPTION ssessesseseesossesossossessossesessossesossossesoosossossossesossossse 5 A ae a a A E E RS 5 2 2 Documentation Standards ui 5 2 5 Naming Convent ons resis did lidia cia 5 2A POST AMINE Standards enan e ena n a a N teeas 6 2 3 S0ftWate Development TOOLS sion 11 Section 3 PHYSICAL DESIGN essesseseesoesessosseseosossesossossescosossossossesossossesossossessosossossossee 12 O ase ees 12 3 2 The Process Model i oi oe A ia en ves eee Ah teas deed a e 12 3 3 Inter Process Communication tras 13 EE ME aa 13 A ATCHIVES Processing Cai 15 3 6 Distribution processing Chain cooocccnnoccconocononoconononononononnnoncnnnnnonononononnnonnnnronncninnnos 18 3 6 1 Control of the Processing Chain A 18 3 7 Directory Structure oeei n a A ias 19 3 7 1 Top Level Directory Structure igor identico 19 3 7 2 Structure of the config Directory diodes 20 3 7 3 Structure of the data Directory viii 21 3S ie Namie Conventi ns AAA a a E E meses 24 HNS O 25 30 System Close DOWN st tios tias 25 3 11 Controlled Termination of Processes essssseeesrsesesressessresressessresressees
137. phical position 6 2 1 Locating the satellite s position attitude and viewing geometry In order to navigate an image and prepare a grid of geolocation tie points it is necessary to determine the satellite s position and attitude at each grid line In the case of SeaWiFS where the instrument may be tilted to avoid sun glint the instrument viewing geometry must also be determined There are two possible methods for locating the satellite s position The first is to use the orbital elements of the spacecraft as supplied by NASA or NOAA the other is to use the GPS data taken at the time of the pass Orbital elements are parameters which exactly specify the orbit of a satellite SeaShark can read this data in two forms TLE and TBUS files Typically SeaShark will have a database of TLE files for the SeaStar satellite and a similar database of TBUS files for the NOAA series of satellites This data is stored in the SeaShark orbit data directory which is subdivided into sen sor types and dates If navigating by orbital elements the only option for AVHRR the first step in determining the satellite position is to find the correct orbital element file SeaShark compares the time of the pass with the time of the orbital element files and chooses the file immediately prior to the time of the pass If no orbital element file is found SeaShark reports this error to the user Once the orbital elements have been established SeaShark can propagate th
138. ral design phase 13 2 2 Documentation Standards ESA standards will be followed 3 2 3 Naming Conventions The development directories of Table 2 1 will be used Directory Contents devsw software under development see below misc miscellaneous files Shadow copy of latest software delivered to ESRIN Test test datasets Table 2 1 Development Area Directory Structure The software directories devsw Shadow will be further sub divided as in Table 2 2 Directory Contents bin executable files config configuration files include include files lib library files Table 2 2 Directory Structure of SSEASHARKHOME A full analysis is presented in section 3 7 on page 19 The src sub directory will be divided in a logical manner to the level of classes A separate sub directory is used to hold programs and processes At the lowest level separate directories will be used to hold RCS and test files The following naming conventions will be used in the SeaShark C source code e Class names Each separate word of the class name will begin with an uppercase letter and the remaining characters of the word will be lowercase Words be joined together Words which represent acronyms in uppercase are allowed and will be written in uppercase For example CEOSFileDescriptor Page 5 SeaShark Detailed Design Document GENERAL DESCRIPTION SHK DDD 001 Issue 2 0 e File names The name of the file containing a cl
139. re Dark restore pixels for the 8 1385 1400 16 unsigned 8 bands 8 x 16 bit words short Image_Data Pixel interleaved SeaWiFS 1401 unsigned 10280 image data for the 8 bands short 1285 pixels per scan line 1285 x 8 x 16 bit words Stop_Sync Stop sync for the SeaWiFS 21961 unsigned 8 imagery 8 x 16 bit words short Pad Pad 2 x 16 bit words 21977 unsigned 2 short Aux_Sync HRPT auxiliary sync 100x 21981 unsigned 100 16 bit words short Table 5 2 Format of the HMF SeaWiFS HRPT Image Data Record Page 43 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 5 4 SeaWiFS and AVHRR Level 1 Archive Product A Level 1 Archive Product contains the files listed in Table 5 3 The formats of most of these files are the same for SeaWiFS and AVHRR products where there are differences these are explained in the text File Type imagery file navigation data file see Section 5 4 1 land sea mask file coastline file see Section 5 4 2 see Section 5 4 3 calibration data file quicklook file postscript quicklook file catalogue entry file see Section 5 4 6 see Section 5 4 7 acquisition details file orbit data file see Section 5 4 10 see Section 5 4 4 see Section 5 4 5 see Section 5 4 8 see Section 5 4 9 a temporary file exists only on disk when the product is first generated b AVHRR only Table 5 3 Fil
140. represents SeaWiFS level 1B image files DistributeBatchQueue DistributelmmediateQueue represents SeaWiFS level 2 flexible format image files represents the distribute batch queue DistributeQueue DistributionReportEntry represents the distribute immediate queue handler for the distribute queue a report entry containing details of a product which has been distributed represents a position on the Earth ErrorWindow_c EarthLocationPoint EarthRectangle represents rectangular regions of the globe ECEFElements represents Earth Centred Earth Fixed orbit data elements ECIElements represents Earth Centred Inertial orbit data elements ErrorStatus general purpose error handling class for storing error status and error strings functionality associated with the Error Window of the GUI a user request originating from ESRIN User Services ESAOrder ESAOrderElement base class containing common functionality for order classes ESAStationName contains ESA processing and acquistion station names in all there formats used by SeaShark Exabyte Exabyte access functions FastDeliveryProduct FDP_Bounding FDP_pixel_Bounding represents a fast delivery product handles the calculation of FDP corners handles mercator projection corner point calculation for FDPs FDP_stereo_Bounding handles stereographic projection corner point calculation for FDPs ForwardTransformCoef
141. resreeseese 25 page iv SeaShark Detailed Design Document Table of contents SHK DDD 001 Issue 2 0 3 12 Error Handling rios adi 26 A A Salts eae 26 Ll Description 26 A A ot o do de 27 313 3 Task POOL ib a 27 Soll See ANG viduals Tasks neri n a a a a a a 28 313 3 Tas A t e E E E S A ERES 29 AO EI eT ALON AEE E E E E EE 29 3 13 7 Task Example iii 30 FALE Orders kei ioeo naaie NET POT E N EANA TE E EAE T ry EE eee 31 SA TEAM A AS 31 3 142 External Int rface AA a a e E a EA Raa 31 AS Pity SiC AL D ASTA a EEEE E E E EE EEE 31 314 4 EMrOrs vetas tii ia 32 5 145 Mailed Order DITECtOry ern poean E a a S RS 33 STAG Mul Ord r Files ita 33 3 LACIE PEU tas 33 A AS DO ad soean scour eecs ees 33 315 2 Errors evt ind nada 34 Section 4 PROCESSING INTERFACE essesseseesossesessossessossesossossesossossesossossessossesossossee 36 4 1 Archive Processing visi in 36 4 1 1 Polling The Import Directories ooooonococnnococonncncnnnnnnnonnnononcnonnnacononcnonnncno 36 4 1 2 Viewing The Status Of Products vacia tias 36 4 1 3 Counting The Products On The System oooooocccconcccconcncooncnononcnonanacinnncnos 37 4 1 4 Selecting Processing Steps ias 37 AAS Viewing The Image siii nidad din 37 4 UM EL Processina seroit a a sayy nse cae a a eae eg aS 37 4 2 1 Polling The Import Directory ooococonococonoccnonoccnonnnnnnnncnnnnncncnnnccnnonannnnnnnos 37 AD De A eat eats 37 4 2 3 Sending Status Piles viii aii sninn i naan 37 4 24 Pursins
142. rface process Page 90 SeaShark Detailed Design Document 72 3 Classes COMPONENTS SHK DDD 001 Issue 2 0 A list of the classes used by SeaShark excluding those from external packages is given in Table 7 2 Further information is available in the source code header files AnnotationDataFlexReadOnly Class Name Description AcqArchReportEntry represents an acquisition and archive report entry AffineCoefficients represents a single sets of affine transformation coeficients that are used to transform from image row column to latitude and longitude and vice versa AlgTestParameters represents the L2 algorithm test parameters used to control output AncillaryAgent supports ancillary data extraction for SeaWiFS L2 AnglePoint represents points defined by two angles azimuth and elevation AnnotationData represents the annotation data file generated for L1 and L2 products AnnotationDataFlex represents the annotation data file generated for SeaWiFS L2 a read only representation of AnnotationDataFlex AQTIM represents the AQTIM DAT file of the SHARK system ArchiveBatchQueue represents the archive batch queue ArchivelmmediateQueue represents the archive immediate queue ArchiveMediaID represents an archive label ArchiveQueue handler for the archive queue AuxDataFile represents a climatology or meteorology data file for SeaWiFS L2 AuxFileName defines an auxiliary data file name AuxQuer
143. riable Description _task_queue Linked list of tasks in the queue _queue_store File for storage of task queue store This name is supplied by a con figuration parameter eg process_immediate_queue _loaded_ok Boolean indicating the load status of the task queue store file _tmp_suffix File name extension for temporary queue store file default tmp _seawifs_entries Number of SeaWiFS tasks in the queue _avhrr_entries Number of AVHRR tasks in the queue Table 3 11 Task Queue Store data structure 3 13 6 Task creation The following steps show how a new task may be created 1 Create a new Task instance 2 Set the task data members to the relevant values using the appropriate member functions Typically these will include SetScheduleState SetSubjectID SetProcessType SetProcessSteps SetSensorType and SetTaskState 3 Save the current global task ID globals gt task_pool global_task_id 4 Use globals gt task_pool next_task to create the new task This will be assigned the current global task ID Page 29 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 5 Check that the task did not already exist by comparing the task ID with the ID saved in 3 above 6 Use update_task to save a copy of the task to disk Some of the member function that are used to handle tasks are shown in Table 3 12 Function Description GetScheduleState Indicates whether the task is on an im
144. rmatted A described in Table 5 4 It is important to note that in the HMF Image Data Record the raw 10 bit HRPT data words are unpacked to 16 bit short words I 2 and that all short words are byte swapped i e a 10 bit word abcdefghi 4 where a is the most significant bit and j is the least sig nificant bit is stored in a 16 bit short word as cdefghij000000ab Further it should also be noted that whilst the State of Health field within the raw HRPT data consists of a series of 8 bit words this data is unpacked as if it were a series of 10 bit words This packing of the data fields is dealt with accordingly by SeaShark during the import process ae Start Sto Size in Name Short Description p Type Times byte byte bytes Frame_Sync HRPT Frame Sync 6 x 16 bit 1 12 12 unsigned 6 words short Spacecraft_ID Spacecraft Identifier 2 x 16 13 16 4 unsigned 2 bit words short Time_Tag Spacecraft time tag 4x 16 bit 17 24 8 unsigned 4 words short SOH_TLM Spacecraft state of health 25 1264 1240 unsigned 775 telemetry 775 x 8 bit words short unpacked into 620 x 16 bit words as if from 10 bit data Inst_Anc_TL SeaWiFS instrument and 1265 1352 88 unsigned 44 M ancillary telemetry 44 x 16 short bit words Gain_TDI Gain and TDI for the 8 bands 1353 1368 16 unsigned 8 8 x 16 bit words short Start_Sync Start sync for the SeaWiFS 1369 1384 16 unsigned 8 imagery 8 x 16 bit words short Dark_Resto
145. rocess When an order is distributed to tape the tape capacity is checked If the quota for the device defined within the configuration file is reached the task is placed in an error state 4 2 10 3 Interactive Orders An interactive order is created using the Interactive Control window which is displayed by Page 39 SeaShark Detailed Design Document PROCESSING INTERFACE SHK DDD 001 Issue 2 0 selecting an archive product from the Task List window and selecting the Process button The Display window will also appear if the archive product is not from an optical disk so that the desired part of the archive product can be selected optical products are already formatted by ESRIN and fixed at 1440 lines in length When the image is displayed the start and stop lines are overlaid in red and can be moved by the operator using the arrow keys in the Interactive Control window The times shown to the left of the text boxes will be written into the order when it is generated and the line numbering starts at zero and is inclusive i e if the start line shows 1 and the stop line shows 498 the final product will contain 498 lines When the operator is happy with the settings in the Interactive Control window an appropriate order will be generated when a selection from the Accept menu is made This order file is placed in the SEASHARKHOME data telecom in orders directory and processed in the same way as any other order 4 3 Immediate
146. rrection for SeaWiFS level 2 products SeaSharkBase base class for device handlers SeaSharkConstants contains all the useful constant values that SeaShark uses such as the raduis of the earth and 7 SeaSharkFile extends RWFile to detect disc full over NFS SeaSharkGlobals contain global classes used by SeaShark SeaSharkMessage provides low level messaging capability SeaSharkTime repesents time down to units of milliseconds as required by SeaShark SeaWIFSxxxx describe different parts of SeaWIFS format files The classes allow the read ing and writing of sections of an SeaWiFS scan line The classes also allow access to individual fields in a section Details of the SeaWiFS formats can be found in 38 and 40 SeaWiFS_L2A_ Algorithm SeaWiFS_L2B_Algorithm encapsulates processing algorithms for SeaWiFS level 2A products encapsulates processing algorithms for SeaWiFS level 2B products SeaWiFS_L2C_Algorithm SeaWiFS_L2FDP_Algorithm encapsulates processing algorithms for SeaWiFS level 2C products encapsulates processing algorithms for SeaWiFS level 2 FDPs SeaWiFS_L2Flex_Algorithm SeaWiFSCalibration encapsulates processing algorithms for SeaWiFS flexible format products SeaWiFSDistributionProduct SeaWiFS_FDPData encapsulates SeaWiFS calibration for CEOS products base class for SeaWiFS distribution products stores information about a SeaWiFS FDP image SeaWiFS_FDPText SeaWiFSDarkRestorePixel
147. ry 1s divided into a number of lines The classes allow the reading and writing of the lines from and to a file They also allow access to individual fields in a line Details of the lines and fields in each line are given in Ref 20 and Ref 21 Catalogue the local archive of catalogue entries on disc It provides functions for open ing and closing the archive CatalogueEntry an individual catalogue entry It provides functions for reading and writing and searching for Catalogue Entries CatMetaLinel the first meta data line of the catalogue entry format CatMetaLine2 the second meta data line of the catalogue entry format CatMetaLine3 the third meta data line of the catalogue entry format CatMetaLine4 the fourth meta data line of the catalogue entry format CatMetaLine5 the fifth meta data line of the catalogue entry format CCT CCT access functions CEOS xxxx describe different sections of a CEOS format file The classes allow the reading and writing of CEOS sections from and to a file The classes also allow access to individual fields in a CEOS section Details of the CEOS formats can be found in Ref 20 and Ref 21 CEOSAttitudeInfo represents the satellite attitude information for SHARP CEOS products CEOSAVHRRHistogramData represents histogram data for all five bands of an AVHRR image CEOS AVHRRSceneHeader represents the scene header of SHARP products CEOSAVHRRSharpVolDirFile represents the VDF of a SHARP product C
148. s 5 Table2 Ctt Codina RUS A aaa 7 Table 2 4 C Coding Recommendations oococcnncccnnoccconnncnnnnanonnnanonnnanonnnonoonnnnconnccconnccnnnnos 9 Table 2 5 C Coding Portability Recommendations ococcnncccnonononnnnonnnannnonnncnn nono nonancnnnnoos 11 Table 3 1 Inter Process Messages ainia ess 14 Table 3 2 Inter Process Message Format A 15 Table 3 3 Steps in the Archive processing chain ooooocnnncccnnncccooncncnoncnononnnononcnononcncnnnacinnnos 17 Table 3 4 Steps in Distribution processing chain ooococnnncccnoncccnoncnonnnnncnnnnnononcnononcnonnccinnnos 18 Table 3 5 SeaShark Directory Content ssssesesssesssseessstesseesseesseresseeessresseesseesseeessseessrese 20 Table 3 6 Content of the data Directory top level oooonocccnnncccnnncccnoncccnoncncnnncnonnnanonanaconnnos 22 Table 3 7 Content of the data Directory iaa tte 23 Table 3 8 Task POO data Structure treri E E E E E E E e 27 Table 3 9 Task data Sur a 28 Table 3 10 Task Pormdata SuiC lune osne a E A a A 28 Table 3 11 Task Queue Store data structure ooooooononccnnononononanonocnononnnnononnnnocononnananonnnnnconon 29 Table 3 12 Selected task member functions sccccsccdsscccsaasceseiesyansecesisesd cacssactadevarsecerssassaanss 30 Table 3 13 CASE Errors A da inicia 32 Tabe 3 14 PrO eS A PO T A n i a iee 34 Table 5 1 AO IMD AT Format a ii rii i A i a A 42 Table 5 2 Format of the HMF SeaWiFS HRPT Image Data Record ooooccccocccccoccccnonccnnnnos 43 Table 5 3 Files in
149. s of other objects such as files This class handles the conversion of DCW names from DOS to UNIX format DCWTile represents a tile within the DCW Tiles make up the DCW libraries DCWVPFTable represents a file in VPF format All data in the DCW is stored in standard VPF format This class allows access to VPF files DeviceHandler abstract base class for device handlers DeviceKernel provides functionality for device handlers DeviceMessageEntry used internally to store connection information Dir provides directory handling functionality DirectoryProduct represents products which hold their data in a product directory Table 7 2 Classes Used by SeaShark Page 95 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 Class Name Description DirEntry represents directory information for use by Dir DisplayCallbacks_c a class encapsulating callback functions used by the Display Window DisplayProduct DisplayWindow_c DisplayWindow_d represents displayable products functionality associated with the Display Window of the GUL DistnSeaWiFSImage DistnSeaWiFSImagelA encapsulated data associated with the Display Window abstract base class for SeaWiFS distribution product image files DistnSeaWiFSImage1B DistnSeaWiFSImage2A represents SeaWiFS level 1A image files represents SeaWiFS level 1B image files DistnSeaWiFSImage2B DistnSeaWiFSImage2Flex represents SeaWiFS level 2A image files
150. sed by SeaShark to interpolate these attitude values QA of these attitude values against valid limits set in the SeaShark configuration file is carried out as for the GPS data Finally in the case of SeaWiFS the instrument tilt is determined by examining the tilt state telemetry in the HRPT see 38 Depending on the tilt lock instrument tilt of 20 0 or 20 degrees is assigned The AVHRR instrument does not tilt and so no adjustment to viewing geometry is required 6 2 2 Generating the navigation grid Now that the satellite position and attitude with instrument tilt state for SeaWiFS is known the geographical position of evenly spaced pixels is calculated the grid spacing is specified in the SeaShark configuration file This information makes up the navigation grid For each grid point the interception of the instrument view with a geoid model of the Earth is made using the Puccinelli algorithm see 14 and the latitude longitude solar angles and satellite angles are recorded Figure 6 1 below shows a navigation grid for a pass over North America Figure 6 1 An example of an interpolated navigation grid Once the navigation grid has been calculated the Interpolate_Navigation_Data program inter polates within the grid so that the x spacing of the grid is exactly equal to one pixel The last stage of the navigation process occurs when SeaShark needs to calculate the pixel position of
151. sful Every program in the processing chain must write such a log file since it is the means by which SeaShark maintains control A Log File contains two lines Line 1 Contains two fields Success and Error_code The Success field is set to either 1 to indicate a successful status or 0 for a failure The Error_code is a program specific number which defines the cause of failure if any Line 2 Contains a string describing the fault if any The following example from a failed Level 0 import process illustrates the format 077 Input image does not contain any valid GPS data Page 67 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 5 11 MEDIA FORMATS This section details the formats used to store information on archive and distribution tapes It should be noted that individual fields within a format are written to tape using the Rogue Wave class RWpostream and read in using RWpistream These classes act as an ASCII veneer over an associated streambuf and are responsible for formatting variables and escaping charac ters in such a way that the results can be interchanged between machines Therefore the infor mation in this section is only valid if these classes are used reading the data off the tape using some other method may produce different results See 41 for further information 5 11 1 Archive Tape An archive tape provides the means for the long term storage of Level 1 products Products are
152. shown in the process model of Figure 3 1 Media Handler gt Process Processor Steps S S Device Hardware Devices S A Figure 3 1 Process Model In Figure 3 1 an ellipse represents a process and a line between two ellipses represents a com munication path between two processes SeaShark contains the following processes e User Interface provides the graphical user interface It is responsible for the following processing displaying the windows of the interface to the operator receiving operator input through the windows sending processing request messages to the Processor sending device access messages to the Media Handler receiving asynchronous status messages returned by the Processor receiving asynchronous status messages returned by the Media Handler carrying out some processing tasks without recourse to the Processor controlling the flow of processing through the system e Processor carries out the main processing steps It is responsible for receiving and parsing request messages from the User Interface initiating the appropriate process step with the correct arguments Page 12 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 monitoring the progress of the processing step by reading log files which the proc ess generates coordinating the sequential execution of several pr
153. signed 1 which was calculated using the int Pucinelli algorithm 14 25 2 29 Table 5 9 Format of the Grid Dimensions structure Name Short Description a Type Times Scan_line_ Copy of the scan line flag from Binary 1 flag the product s image with an unsigned additional flag defining if the short line was calculated or interpo lated Day of year of the line unsigned 1 short Milliseconds Millisecond since midnight of unsigned 1 the line int Grid_Point Definition of the lat long sun Structure Variable Values and satellite angle at a grid Table 5 11 point Table 5 10 Format of the Grid Row structure a Number of grid points per line is defined in the Grid Dimension structure see Table 5 9 The relationship between some of the entities from Table 5 9 is illustrated in Figure 5 1 Page 48 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 OQO X X X X X X XI Scan line 1 Oo O O Q O Q Q Scan line 2 0O O O O O O o ol LXX X X X X X X O O O O O O O Lo o oO oo o_o Ol X X X X X X X O O O O O O O Log o oo o o Ol X X X X X X X Scan line n Figure 5 1 Grid Dimensions structure x navigated pixel o interpolated pixel Calculated_Rows number of scan lines containing x Y_Spacing the gap number of scan lines between scan lines containing x Y_Origin the number of the first scan line containing x omer Start Stop Siz
154. ssescosoesossossesossossesossossessossesossossee 72 O 12 GV FER PA UN OEl einean a a a a a 72 6 1 2 Level DD yd li 73 6 2 The Navigation Prode incitan 74 6 2 1 Locating the satellite s position attitude and viewing geometry 74 6 2 2 Generating the navigation grid c oocoononcccnoncccnoncnononcnonnnanononcnnnnnc conca cnannnnnns 75 6 2 3 Geographic location to pixel position ooooocoocccconcccnoncnononcnononanonancnonnncnnnns 76 6 2 4 Navigation data summary cocooocccconccconncnononanonnnanononononnnnnnnnnnconnccnnnncnnnnncnnns T11 6 2 5 A a O e E a iat 77 63 TOV LN 6 tec eee ee te grata at cA a at ene tabetha anh tone EREN 78 A Soar ads Go RSet Paani tal Mein 80 6 DCTS edad ea E cad Ns o dd dd de 80 O OSREGAIN tl ras 80 6 7 Orbit SUtCOIME acordo aliada diia 80 RA ig haired eyelet cae ei ue ae ee nak eee eg asta ae 81 A A ir e Pecan dat capac 81 6 10 AVHRR Distribution Product OverView ooooocccnoncccnoncccnoncnononcnononancnnncnnnnncnnnnnos 83 6 11 Calibration of visible AVHRR channels 000 0 eeeeeeeseeceeececeeeeeceeeeeeeteeeeeeeeesaes 83 6 11 1 Even numbered satellites coin aiii 83 6 1122 Odd mimbered satellites sencon n E RRE R 84 6 12 Calibration of Thermal AVHRR channels oooooconnncccnoccccnoncnononcnononcnononcnonnncninnnos 84 6 12 1 Calculation of Spectral Radiance ooonocccnnococcnncccnoncnononcnononanononcnonananonns 84 6 13 NOAA KLM and the AVHRR 3 type instrument c cooooccccnnccccnnnncnoncnononcnonnnaninn
155. t CEOSSatelliteInfoL2 represents the satellite information for a level 2 CEOS product CEOSSeaWiFSAuxDataRecord represents the auxiliary data record of a SeaWiFS flexible format CEOS product CEOSSeaWiFSComplr represents the composite and irradiance record of a SeaWiFS flexible format radRecord CEOS product CEOSSeaWiFSGeophysParam represents the geophysical parameter record of a SeaWiFS flexible format Record CEOS product CEOS SeaWiFSL2LeaderFile represents the leader file for a SeaWiFS level 2 CEOS product CEOSSeaWiFSLeaderFile represents the leader file for a SeaWiFS CEOS product CEOSSeaWiFSSceneHeader represents the scene header record for a SeaWiFS CEOS product CEOSSeaWiFSThreshCorrDa represents the thresholds and correction data records for a SeaWiFS flexible taRecord format CEOS product CEOS SeaWiFS VolDirFile represents the VDF for a SeaWiFS CEOS product CEOS SequenceRecordID represents a record ID which ends with a four byte ASCII field CEOS Sharp2LeaderFile represents the leader file for a SHARP level 2 CEOS product CEOSState Vectors represents the state vector information for a SHARP CEOS product CEOSTextRecord represents the text record of a SHARP CEOS product VDF CEOSTiePointLocations represents the tie point location fields in the annotation file of a SeaWiFS CEOS product CEOSTrailerFile represents the trailer file of SHARP CEOS products CEOS VolDirFile represe
156. t Delivery Products which are copied into the telecom out directory Refer to 9 for more information 6 16 Delete All files and directories associated with the product created are deleted from the disk 1 SeaDAS software may be freely downloaded from NASA http seadas gsfc nasa gov Copyright is acknowledged Page 88 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 7 COMPONENTS 7 1 Graphical User Interface The GUI has been created using Sun WorkShop Visual 2 0 a software tool written specifically for the purpose of making the design and implementation of X Motif graphical user interfaces easier WorkShop Visual allows the creation of complex widget hierarchies through a graphical representation of the hierarchy and allows the user to view the window immediately without having to compile any code first The definitions of all the windows used in SeaShark are stored in a file named shark xd which is generated by WorkShop Visual when the design is saved The widget resources are stored in the Xdefaults SeaShark file Each window in SeaShark has 1ts own widget hierarchy with the parent widget always being a shell widget Shell widgets may be one of three types a TopLevelShell an ApplicationShell or a DialogueShell There is only one ApplicationShell in SeaShark the SeaShark Main Window and all other windows are DialogShell windows which are children of the Main window This means that the SeaShark application
157. t Stop Size in Name Short Description Type mission_id mission identifier ASCII e g SSI or N11 blank ASCII SWF or AVH sensor_id sensor identifier ASCII FDP pro_level product level blank pro_type product type ASCII e g SST or NDVI blank gt blank Table 5 23 Format of the FDP Description File Page 56 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 Start Sto Size in No Name Short Description P Type Pido Bethe ot 5 SW_1 software id and version ASCII e g SeaShark_2 0 processing centre ASCII e g TMS acquisition date ASCII YYMMDD original level 1 product id ET ASCII e g 9308280745TMN1 processing date 67 67 ASCII YYMMDD 1 output image format 68 70 71 71 72 3 ASCII e g RAW or GIF 1 12 image sub sampling fac ASCII nn tor 1 13 img_width output image width 4 ASCII nnnn blank 81 sl 1 14 img_height output image height 82 85 4 ASCII nnnn 86 1 15 number of pixels 90 4 ASCII nnnn extracted in x 91 1 16 number of pixels 95 4 ASCII nnnn extracted in y 96 1 17 i image projection 104 8 ASCII e g SATELLIT or MERCATOR 105 105 1 18 A latitude of the image cen 106 112 7 ASCII F6 3 tre 113 113 1 19 longitude of the image 114 121 8 ASCII F6 3 centre 122 122 1 Table 5 23 Format of the FDP Description File The FDP form
158. tart date and time of the 16 27 12 ASCII and_time report YYMMDDhhmmss Table 5 29 Format of the Second Header Line of a Report Page 63 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Is sue 2 0 aoe Size in No Name Short Description byte byte bytes blank 28 28 1 3 link_text 29 33 5 ASCII Vandy blank 34 34 1 4 end_date_a end date and time of the 35 46 12 ASCII nd_time report YYMMDDhhmmss blank 47 47 1 endline endline character 48 48 1 Table 5 29 Format of the Second Header Line of a Report where V represents a space character The report line of the Acquisition and Archiving Report is formatted as shown in Table 5 30 Start Stop Size in No Name Short Description Type P byte byte bytes YP 1 date date of the operation 1 10 10 ASCII YYYY MM DD blank 11 11 1 2 pass_ID passage identifier 12 27 14 ASCII YYMMDDhhmmaass where da acquisition station ss sensor blank 28 28 1 3 pass_start_ start time of the 29 47 19 ASCII time acquired pass YYYY MM DD hh mm ss blank 48 48 1 4 pass_stop_ stop time of the 49 67 19 ASCII time acquired pass YYYY MM DD hh mm ss blank 68 68 1 5 archived_s start time of the 69 87 19 ASCII tart_time archived pass can be YYYY MM DD hh mm ss different from field 3 blank 88 88 1 6 archived_s stop time of the 89 107 1
159. te Acquisition start date 6 ASCII YYMMDD new line char 1 acq_start_time Acquisition start time 9 ASCII HHMMSSmmm new line char 1 acq_stop_date Acquisition stop date 6 ASCII YYMMDD new line char 1 acq_stop_time Acquisition stop time 9 ASCII HHMMSSmmm new line char 1 no_scan_lines Number of scan lines 4 ASCII within the passage nnnn new line char 43 43 1 Table 5 1 AQTIM DAT Format Note The start and stop dates and times refer to the times of the first and last lines in the HRPT file Example Vil 930828 074558987 930828 075341320 2775 where V represents a space character 5 2 SeaWiFS HRPT Product The processing of a SeaWiFS HRPT pass requires only the SeaWiFS HRPT Level 0 file There is no currently defined SeaWiFS equivalent of the AVHRR AQTIM DAT file an empty file is used to trigger import 11 Page 42 SeaShark Detailed Design Document FILE FORMATS SHK DDD 001 Issue 2 0 5 3 SeaWiFS HRPT Level 0 File Formats There are three formats of the SeaWiFS HRPT Level 0 file accepted by SeaShark The first is the raw HRPT data as acquired from the satellite 38 SeaShark also accepts HRPT data as re formatted by acquisition software into either NASA Frame Formatter Level 0 40 or HMF SeaWiFS HRPT format 45 The HMF SeaWiFS HRPT data format in use for example at Scanzano ground station con tains a series of Image Data Records one per minor frame each of which is fo
160. te is recognised when a coherent block of scan lines greather in length than the coherent tilt length defined in SeaShark cfg import_coherent_tilt_length and thereby protecting against occa sional noise affected tilt telemetry shows a new tilt state Image scan lines acquired during tilt transition are discarded The following files are created for the imported Level 0 product or for each of the split image products identified in step 4 e AQTIM DAT AVHRR only Refer to section 5 1 2 for description of file format e image lla Refer to section 5 4 1 for description of file format e catalogue iuf Refer to section 5 4 8 for description of file format All the files that are created are temporarily stored in lt Product_ID gt IMP directory but then moved to lt Product_ID gt directory on successful completion of all steps For the catalogue iuf the elements filled after successful import are e MetaLine 1 e Mission ID e Sensor ID e Data mode Page 72 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 Acquisition date Start time End time Station ID Metaline2 e Product ID e Band modes e QI flag e MetaLine3 Number of lines e Number of bad lines e Number of gaps e Delta time Delta roll Delta pitch Delta yaw e MetaLine4 e MetaLine5 e MetaLine6 e MetaLine7 e MetaLine8 e MetaLine9 If import fails an error is reported to the user and an HRPT_IMAGE LOG file is added to the i
161. the code OR Passes may be specified by product name or timing criteria all are assumed to be available in the local image directory May be used with AVHRR and SeaWiFS imagery An error is generated if a scanning is present in the optional passes but absent from the selected pass list For more information refer to 9 6 8 Retrieve Checks whether the necessary archive product exists on disk If the archive product does not exist on disk the current archive tape is searched or optical disk for optical retrieval If the archive product does not exist on tape the retrieve fails Refer to 9 for more information 6 9 Generate The distribution product files are created or copied for optical Sharp1 products In Table 6 1 and Table 6 2 are listed the files created for each type of distribution product and the executa ble used to create them Distribution product Executable used File created Sharpl Create_AVHRR_Sharpl VDF from archive product NULL_VDF LEADER IMAGE TRAILER Sharp2A Create_AVHRR_Sharp2A VDF from archive product NULL_VDF LEADER IMAGE TRAILER Sharp2B Create_AVHRR_Sharp2B VDF from archive product NULL_VDF LEADER IMAGE TRAILER Sharp2A Processes_Sharp1_to_2A VDF from optical product NULL_VDF LEADER IMAGE TRAILER Table 6 1 Distribution product types AVHRR Page 81 SeaShark Detailed Design Document PROCESSING STEPS SHK DDD 001 Issue 2 0 Distribution product
162. the task queues Page 28 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 3 13 5 Task queues There are two types of task queue used in SeaShark e Immediate The next queued task will become active as soon as the current active task on this queue completes e Batch When batch processing is activated the tasks on this queue are transferred to the associated immediate queue for processing This type of queue acts as a holding store tasks are not processed directly from it There are four queues of each type e Archive This queue handles tasks for archiving post archiving deletion and retention as reference products e Distribute This queue handles tasks for distribution and post distribution deletion e Retrieve This queue handles retrieval tasks e Process This queue handles all other processing The data members of the TaskPool are shown in Table 3 8 Tasks are placed on the relevant queue either by operator action or automatic detection of import products or orders The task state is set to Waiting Queued On every SeaShark timer event the four immediate queues are polled If the queue is not active the first waiting task is serviced When a sequence of processing steps is in progress the task is moved as necessary from one queue to another In practice this only involves tasks in the processor queue which may be moved either to the archive queue or to the distribute queue Va
163. tie_points_per_line x sizeof int x angles_per_tie_point So for AVHRR products where 65 points are calculated per line record_length 8 65 x 4 x 6 1568 Bytes For SeaWiFS products where 55 points are calculated per line record_length 8 55 x 4 x 6 1328 Bytes The number of data records in the file is the same as the height of the related image This gives a one to one relationship between image line and navigation line The navigation data lines are calculated in one of two ways by direct calculation from the predicted orbital position of the satellite using the Puccinelli algorithm or by interpolation from the directly calculated values Note that in SeaShark the regular grid of points is forced to have a row spacing exactly equal to one pixel During the navigation process grid lines are calculated with a spacing greater than one for performance reasons and then the intermediate line values are interpolated from the calculated ones The navigation data file is binary with the format shown in Table 5 8 Start Stop Size in Name Short Description byte ie Type Times Grid_Dims Dimensions of the navigation Variable Variable Structure 1 grid Table 5 9 Grid_Row Row of grid point values Variable Variable Structure Variable Table 5 10 Table 5 8 Format of the Navigation Data a The size of the Grid_Dims structure is fixed at 36 bytes However to maintain a fixed record length
164. tion generates linearly interpolated values OceanFDP level 2 processing for SeaWiFS FDPs OceanL2A processing for SeaWiFS level 2A products OceanLevel2 processing for SeaWiFS level 2 products OptionalCMDArg used internally by CmdArg OrbitDataMgr handles the SeaShark TBUS and TLE archive which is stored on disc The physical storage mechanism is encapsulated and hidden from users of the class OrbitStitchConfig represents the config file for the orbit stitching process Order reads orders requests for a specified product to be generated by an acquisi tion station received from ESRIN OrderFormCallbacks_c OrderFormWindow_c class encapsulating callback functions for the Order Form Window functionality associated with the Order Form Window of the GUI handles the import and moving of order files OrderHandler OrderStatusEntry represents an entry in an order status file OverlayCallbacks_c class encapsulating callback functions for the Overlay Window Overlay Window_c functionality associated with the Overlay Window of the GUI OzoneMetDataLoader functionality to ingest ozone meteorology data files into SeaShark Parameter represents parameters in the radiometric ancillary recordof the SHARP level 2 leader file PARTable PAR library functions PassCoverage represents temporal coverage by a series of passes Table 7 2 Classes Used by SeaShark Page 99 SeaShark Detailed Design Document
165. uirements Definition Phase ESA BSSC October 1991 Object Oriented Design G Booch Benjamin Cummings 1991 Ground Location of Satellite Data Puccinelli Photogrammatic Engineering and Remote Sensing Vol 4 4 April 1976 Digital Chart of the World VPFVIEW Users Manual for DOS Version 1 0 July 1992 Digital Chart of the World Vector Product Standard Defense Mapping Agency Novem ber 1990 Digital chart of the World DCW Product Specification Defense Mapping Agency November 1990 Solaris 2 0 Transition Planning Guide for Application Developers Sun Microsystems Inc 1991 Pipeline to Solaris 2 0 A Porting Reference Guide for Software Developers Sun Micro systems Inc 1991 SHARP 1 Technical Specification of CCT Format Release 1 1 ESA EPO February 1991 SHARP 2 Technical Specification of Format Release 1 0 ESA EPO March 1992 Bad Line Philosophy ESRIN DPE OT JMM 93 001 Issue 1 4 OSF Motif Style Guide Version 1 Open Systems Foundation 1990 EO Formatting System Instrument Data Product Format SeaWiFS LAC 1A EOFS IDF 002 TN 2 1 4 April 1995 EO Formatting System Instrument Data Product Format SeaWiFS LAC 1B EOFS IDF 003 TN 1 1 9 August 1995 EO Formatting System Inventory Exchange Format SeaWiFS Inventory Update File SIUF Specification EOFS IEF 002 TN 2 2 2 March 1995 SeaShark System Specifications Annex A DPE OT JMM 93 001 Issue 1 4 SeaShark Software Data Format Definitions
166. ument FILE FORMATS SHK DDD 001 Issue 2 0 Each directory entry describes one of the products on the tape The format of a Directory Entry 1s given in Table 5 37 No Name Short Description Format 1 Time Time the product was written to tape internal format RWTime new line char 2 File name Name of the product Product ID ASCI e g 9308280745TMN1 3 Size Size of the product in bytes ASCII new line char 4 Offset Position of the product on the tape in terms of number of tar files e g the first product has offset 1 etc new line char Table 5 36 Format of the Archive Tape Directory Entry Product tar files contain nine datafiles which together form a single archive product Each file is named with the Product_ID as a directory name to aid identification i e ProductID ProductFile When untarred from the tape each product expands into a number of files from which the product is composed The files are automatically placed by SeaShark into a directory struc tured according to SEASHARKHOME data sensor Level1 ProductID The product files are listed in Table 5 37 Name Content image lla Image data navigation Navigation data quicklook rs QuickLook paper_ql ps Postscript QuickLook land_sea_mask Land sea mask catalogue iuf tbus tle Catalogue entry Orbit data calibration AQTIM DAT Calibration data Acquisition details Table 5 37 Archive Tape a Sea
167. us Files to ESRIN These interfaces are specified by the formats of the ESA Order and Order Status files and the directory structure used for file exchange The formats of the files are defined in 36 standing orders are not supported with clarification of the order status codes provided in email mes sages from ESRIN The file names and directory structures are defined below 3 14 3 Physical Design SeaShark uses three directories to store orders e an import directory SEASHARKHOME data telecom in orders into which new ESA Order Files from ESRIN are placed This is done by an external telecommunications system and is outside the scope of SeaShark No assumptions are made about the names of files in the import directory e a store directory SSEASHARKHOME data orders Store into which orders are placed ready for processing The store directory is sub divided into directories uniquely labelled using the order code and sub order number taken from the Order Each subdirectory con tains two files a copy of the ESA Order File named Order and an Order Status File named OrderStatus export directories SEASHARKHOME data telecom out orders into which Order Status Files are placed for transmission to ESRIN and SEASHARKHOME data telecom out fdp into which FDP products are placed The transmission is the responsibility of an exter nal telecommunications system and is outside the scope of SeaShark The fdp directory is sub
168. wer improved version Page 15 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 IMPORT PRODUCT LEVELO PRODUCT Get Orbit Data Navigate Coastline Coastline does Coastline not match matched Mask bration Data Interpolate Navi gation Data enerate Quicklook Update Catalogue Quicklook LEVEL1 PRODUCT ee a Figure 3 2 Archive processing chain Page 16 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 Figure 3 2 describes the execution sequence of the steps Table 3 1 describes the steps in the processing chain See Section 6 for a complete description Processing Step Import Description Automatically recognises new passes of AVHRR or SeaWiFS HRPT data checks their quality and reformats them to Level 0 The program Import_AVHRR_Product or Import_SeaWiFS_Product is used Get Orbit Data Navigate Locates the most up to date orbit data in the form of a tbus message for use in the navigation The program Get_Orbit_Data is used Calculates the geographical location sun angles and satellite angles for a grid of pixels in an imported image and stores them in a separate file The programs Navigate_AVHRR Navigate_SeaWiFS_GPS and Navigate_SeaWiFS_TLE are used Extract coastline Coastline matching Extracts from the DCW the co ordinates of all coastline segments within the are
169. y The telecom directories are used for the electronic transfer of data between an acquisition sta tion and the central ESRIN site SeaShark exchanges information with several external systems by file transfer over a network Files to be sent to an external system are placed in the tele com out directory The directory is divided into a number of sub directories for different data types as shown in Figure 3 6 Page 23 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 BROWSE CATALOGUE UNNOS00 94 TELECOM_OUT REPORT Figure 3 6 Structure of the telecom out Directory The directory telecom out contains a number of directories into which different types of data are placed ready for transmission to ESRIN The type of data stored in each directory is self explanatory Note that the directories FDP and ORDER are further divided by USER_ID ORDER_ID and SUB_ORDER_ID 3 8 File Naming Conventions The Software User Manual 10 defines the naming conventions and formats of files used by SeaShark Some of the file formats are defined externally to SeaShark whilst some are defined within the SeaShark project For the former a reference is made to the relevant documentation for the latter a reference is made to the appropriate section of this document Page 24 SeaShark Detailed Design Document PHYSICAL DESIGN SHK DDD 001 Issue 2 0 3 9 System Start up SeaShark is started by executing the User Inter
170. yManager base class controllong access to the auxiliary data files AVHRR_ Channel AVHRR_FDPData represents AVHRR channel 3 functionality for NOAA KLM represents an AVHRR Fast Delivery Product AVHRR_FDPText stores descriptive information about the FDP AVHRRBackScan represents AVHRR back scan data AVHRRCalibrationFields represents AVHRR calibration data fields AVHRRChannelResponse represents a table of AVHRR IR response versus wave number AVHRRHRPTImage represents raw AVHRR HRPT image data AVHRRHRPTImageDLR represents raw AVHRR HRPT image data in DLR format AVHRRHRPTImageDundee represents raw AVHRR HRPT image data in Dundee format AVHRRHRPTImageNASA represents raw AVHRR HRPT image data in NASA format AVHRRImportProduct represents the AVHRR level 0 data in its lowest form AVHRRL2A lgorithm represents parameters and algorithms for AVHRR level 2 processing AVHRRLashamImage provides I O functionality for AVHRR lasham images RAE format AVHRRLevel0Image provides generic I O and access to non instrument specific aspects of AVHRR Level0 images AVHRRLevel0Product represents AVHRR level 0 products AVHRRLevel Image represents AVHRR level images AVHRRSensor common features of all AVHRR sensors Table 7 2 Classes Used by SeaShark Page 91 SeaShark Detailed Design Document COMPONENTS SHK DDD 001 Issue 2 0 Class N
171. ys have the file name extension cc Rule 3 Inline definition files always have the file name extension icc Rule 4 Every file that contains source code must be documented with an introductory comment that provides information on the file name and its contents Rule 5 All files must include copyright information Rule 6 All comments are to be written in English Rule 7 Every include file must contain a mechanism that prevents multiple inclusions of the file Rule 8 When the following kinds of definitions are used in implementation files or in other include files they must be included as separate include files classes that are used as base classes classes that are used as member variables classes that appear as return types or as argument types in func tion member function prototypes function prototypes for functions member functions used in inline member functions that are defined in the file Rule 9 Definitions of classes that are only accessed via pointers or references amp shall not be included as include files Rule 10 Never specify relative UNIX names in include directives Rule 11 Every implementation file is to include the relevant files that contain declarations of types and functions used in the functions that are implemented in the file declarations of variables and member functions used in the functions that are implemented in the file Rule 12 The identifier of every globally visible class enumeration type type definition function

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