PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 577 FILE_RECORDS = 174 /* POINTERS TO FILE OBJECTS */ ^HEADER_TABLE = ("PVOUVS0296_TM.DAT",1) ^DATA_TABLE = ("PVOUVS0296_TM.DAT",2) /* IDENTIFICATION DATA ELEMENTS */ DATA_SET_ID = "PVO-V-OUVS-2-EDR-VENUS-V1.0" SPACECRAFT_NAME = "PIONEER 12" SPACECRAFT_ID = "P12" INSTRUMENT_HOST_NAME = "PIONEER VENUS ORBITER" INSTRUMENT_ID = "OUVS" INSTRUMENT_NAME = "PIONEER VENUS ORBITER ULTRAVIOLET SPECTROMETER" PRODUCT_ID = "PV0296F.TM" ORBIT_NUMBER = 296 START_TIME = 1979-09-26T15:50:09 STOP_TIME = 1979-09-27T03:31:48 SPACECRAFT_CLOCK_START_COUNT = "UNK" SPACECRAFT_CLOCK_STOP_COUNT = "UNK" PRODUCT_CREATION_TIME = 2013-07-02T18:59:01 /* DESCRIPTIVE DATA ELEMENTS */ TARGET_NAME = {"VENUS","STAR", "INTERPLANETARY_HYDROGEN"} WAVELENGTH = {1011,1213,1301,1355,1980, 2067} CHANNEL = {"F_CHANNEL", "G_CHANNEL"} GRATING_MODE = "FIXED" DESCRIPTION = " This telemetry file contains the extracted data for the Pioneer Venus Orbiter Ultraviolet Spectrometer(PVOUVS) instrument. The files were written at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado. Dr. Arthur Ian F. Stewart was the Principal Investigator. See the instrument profile document at the PDS site or publication Radio Science, Vol. 8, p.379, 04/1973. These files have been recovered from Vax formatted, optical disk devices, documented and archived in IEEE standard formats as a result of NASA grant NNX09AM04G. These PVxxxxf.tm files are the available set of extracted OUVS orbit data from the mission. The complete set of raw Experiment Data Record (EDR) and geometry Orbit-Attitude (OA) files is available on the LASP website at lasp.colorado.edu. Image files that were previously deposited at PDS, in 1995, were generated from these extracted data files. Unfortunately, the software to convert raw data to images is no longer available in 2011. New software analysis is being developed; look for new information on the LASP website. Also see the information available on disk PDS/data/PV01_1001, and various analysis papers by A.I.F. Stewart and those listed in the catalog reference template. Comet Halley images were not available with the 1995 submission. The raw data from the PVOUVS instrument are present in orbits 2581 through 2585 and 2614 through 2649. A discussion of the analysis is available in the following paper: Pioneer Venus measurements of H, O, and C production in comet P/Halley near perihelion, A.I.F. Stewart, in Astron. Astrophysics 187, 369-374 (1987). A diagram of the file and record structure is shown below: +-------------------------------------------------------+ 0 |File Summary Record (64 Bytes) | |...Zero Fill to End of 576 Byte Summary Record | +-------------------------------------------------------+ 1 | |Science Record Header (64 Bytes) | | |Science Data (256 2 Byte Integers/512 Bytes) | +-------------------------------------------------------+ 2 | |Science Record Header (64 Bytes) | | |Science Data (256 2 Byte Integers/512 Bytes) | +-------------------------------------------------------+ . . repeats to final science record . +-------------------------------------------------------+ i | |Science Record Header (64 Bytes) | | |Science Data (256 2 Byte Integers/512 Bytes) | +-------------------------------------------------------+ Record 0 is a file summary record containing orbit, date and time information, as well as the number of records in the file. Records 1 to i are science records. Each science record begins with a 64-byte header containing information about the given block of science data. This header is followed by 256 2 byte integers which comprise the science data. Each 576 byte record is separated by a single 0x0a byte. Note: The FILE_RECORDS keyword includes the summary record as well as the number of science records. Note: The files were created on a VAX machine. They have little endian byte order, and their floating point values are in VAX F and VAX D formats. Summary Record Contents: Item Contents Data Type ------------------------------------------------------------------------- 0 4 Characters: '.TM.' 4 characters 1 orbit number at start 2 byte integer 2 orbit number at end 2 byte integer 3 date at start: YYDDD(spacecraft UT) VAX F floating point 4 second of day at start VAX D floating point 5 date at end: YYDDD(spacecraft UT) VAX F floating point 6 second of day at end VAX D floating point 7 date at periapsis: YYDDD VAX F floating point 8 second of day at periapsis VAX D floating point 9 date of file creation: YYDDD VAX F floating point 10 second of day at file creation VAX D floating point 11 4 characters: 'B1.1'(or B2.1, B3.1) 4 characters 12 unknown integer 2 byte integer 13 number of records in file 2 byte integer 14 zero fill to end of record Note: There are two bytes separating items 11 and 13, characters 'B1.1' and the number of records. Their use could not be determined. Item 4, second of day at start, gives the time of the first byte of the first science record in the file. Item 6, second of day at end, gives the time of the first byte of the last science record in the file. Science Record Header Contents: Item Contents Data Type ------------------------------------------------------------------------- 0 date of start of data (spacecraft UT) VAX F floating point 1 second of day at start of data VAX D floating point 2 dclokz from major frame header VAX D floating point 3 timlen (not used; do not need) VAX F floating point 4 time per minor frame from maj frame header VAX F floating point 5 orbit number 2 byte integer 6 rip value from tm stream, N/A = 0 2 byte integer 7 A command from EDR command log, N/A = 0 2 byte integer 8 B command from EDR command log, N/A = 0 2 byte integer 9 grating position (extracted from A command) 2 byte integer 10 instrument state (buffer in or out) 1 byte 11 Pb in effect at drec, trec 1 byte 12 F or G channel from Pb 1 byte 13 grating drive LED used from Pb 1 byte 14 integration period from B command 1 byte 15 highest value of channel F high voltage 1 byte 16 lowest value of channel F high voltage 1 byte 17 subcomD values array of 5 bytes 18 data format code from maj frame header 1 byte 19 bit rate code from maj frame header 1 byte 20 combination of maj frame header words 1 byte 21 unknown value 1 byte 22 =0 if date/time known, != 0 if not known 1 byte 23 indblk (not needed any more) 1 byte 24 position in minor frame for 1st data value 1 byte 25 first valid word in sync position 1 byte 26 number of data values written out 1 byte 27 numin (not needed) 1 byte 28 spare values (originally) 1 byte 29 =R for reprocessed TM, blank for PV*F.TM 1 character 30 gp from the tm stream 2 byte integer 31 science data array of 256 2 byte integers Items 0 and 1: The timing of the reference pulse defined in the A command(Item 7) dictates the value of the start of data. A Command and B Command are broken up into individual bits. These bits determine the instructions that the Pioneer Venus Orbiter was given A Command Bits: QA-bit # Instruction -------------------------------------------------------------------------- 1 0 = fixed grating, 1 = scanning grating 2 0 = G-channel 1 = F-channel 3 0 = High Voltage Off 1 = High Voltage Off Override 4 |----------------> Spatial Source: 5 | 000 = RAM 010 = NADIR 100 = RIP 6 | 110 = +LIMB 111 = -LIMB 7 | 8 | 9 | 10 |----------------> Grating Position: 11 | 0-511 12 | 13 | 14 | 15 | 16 Steering bit = 0 for QA command B Command Bits: QB-bit # Instruction -------------------------------------------------------------------------- 1 0 = HV normal 1 = HV off 2 0 = Cal Lamp off 1 = Cal Lamp on 3 0 = Buffer Normal 1 = Buffer Empty Override enabled 4 | 5 | 6 | 7 | 8 |---------------> Data Start Delay: 9 | 0-1023 10 | 11 | 12 | 13 | 14 |--------> Integration Period: 15 | 00 = 4 msec, 01 = 16 msec, 10 = 8 msec, 11 = 32 msec 16 Steering bit = 1 for QB command Items 9 and 10: derived from A and B commands and should be consistent. Item 9: Has a range of 0 to 511 Item 12: A value of 0 corresponds to the G-channel. A value of 1 corresponds to the F-channel. Items 12 through 14: these are derived from the A and B commands (Item 7) and should be consistent Item 8: The Data Start Delay in the B command (Item 8) is expressed as a fraction of one rotation. Specifically, n/1024*(2 pi), where n is the delay. Item 31: The data are returns as the number of counts recorded during the integration period. ........................................................................" /* DATA OBJECT DEFINITIONS */ OBJECT = HEADER_TABLE NAME = "TELEMETRY_HEADER" INTERCHANGE_FORMAT = BINARY ROW_BYTES = 577 COLUMNS = 15 ROWS = 1 ^STRUCTURE = "PVTMHEAD.FMT" END_OBJECT = HEADER_TABLE OBJECT = DATA_TABLE NAME = "TELEMETRY_DATA" INTERCHANGE_FORMAT = BINARY ROW_BYTES = 577 COLUMNS = 33 ROWS = 173 ^STRUCTURE = "PVTMDATA.FMT" END_OBJECT = DATA_TABLE END