PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 97 FILE_RECORDS = 709 /* POINTERS TO FILE OBJECTS */ ^HEADER_TABLE = ("PVOUVS0245_OA.DAT",1) ^DATA_TABLE = ("PVOUVS0245_OA.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 = "PVOUVS0245_OA.DAT" ORBIT_NUMBER = 245 START_TIME = 1979-08-06T06:20:48 STOP_TIME = 1979-08-07T08:01:47 SPACECRAFT_CLOCK_START_COUNT = "UNK" SPACECRAFT_CLOCK_STOP_COUNT = "UNK" PRODUCT_CREATION_TIME = 2013-01-19T00:21:41 /* DESCRIPTIVE DATA ELEMENTS */ TARGET_NAME = {"VENUS","STAR", "INTERPLANETARY_HYDROGEN"} DESCRIPTION = " This raw orbit/attitude 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. A diagram of the file and record structure is shown below: +-------------------------------------------------------------------+ 0 |File Summary Record (64 Bytes) | |...Zero Fill to End of 96 Byte Summary Record | +-------------------------------------------------------------------+ 1 | |Orbit Attitude Data (1 float, 1 double, 20 floats, 2 shorts) | +-------------------------------------------------------------------+ 2 | |Orbit Attitude Data (1 float, 1 double, 20 floats, 2 shorts) | +-------------------------------------------------------------------+ . . repeats to final science record . +-------------------------------------------------------------------+ i | |Orbit Attitude Data (1 float, 1 double, 20 floats, 2 shorts) | +-------------------------------------------------------------------+ 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 orbit attitude records. Each 96 byte record is separated by a single 0x0a byte. The 96 bytes are comprised of 1 VAX F floating point, 1 VAX D floating point, 20 VAX F floating points, and 2 two-byte integers 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: '.OA.' 4 characters 1 orbit number at start 2 byte integer 2 orbit number at end 2 byte integer 3 date at start: YYDDD VAX F floating point 4 second of day at start: GMT VAX D floating point 5 date at end: YYDDD VAX F floating point 6 second of day at end: GMT 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 VAX F floating point 1 second of day at start of data: GMT VAX D floating point 2 X position [km] VAX F floating point 3 Y position [km] VAX F floating point 4 Z position [km] VAX F floating point 5 X velocity [km/s] VAX F floating point 6 Y velocity [km/s] VAX F floating point 7 Z velocity [km/s] VAX F floating point 8 X spacecraft to sun vector [km] VAX F floating point 9 Y spacecraft to sun vector [km] VAX F floating point 10 Z spacecraft to sun vector [km] VAX F floating point 11 Transformation Matrix XX VAX F floating point 12 Transformation Matrix XY VAX F floating point 13 Transformation Matrix XZ VAX F floating point 14 Transformation Matrix YX VAX F floating point 15 Transformation Matrix YY VAX F floating point 16 Transformation Matrix YZ VAX F floating point 17 Transformation Matrix ZX VAX F floating point 18 Transformation Matrix ZY VAX F floating point 19 Transformation Matrix ZZ VAX F floating point 20 roll angle VAX F floating point 21 spin rate VAX F floating point 22 unknown value 2 byte integer 23 unknown value 2 byte integer Items 2 through 4: the three components of the spacecraft position vector, in units of km, in the 'ecliptic inertial Cartesian coordinate system.' (see reference from sedr work). In this system, Venus is located at the origin, the first point of Aries is located in the direction of <1,0,0>, and the north ecliptic pole of Venus is in the <0,0,1> direction. Items 5 through 7: the spacecraft orbital velocity in the same coordinate system as the position vector, expressed in units of km/s. Items 8 through 10: The vector from the spacecraft to the Sun in the same coordinate system as the position vector, expressed in units of km. Items 11 through 19: the nine elements of the transformation matrix to convert coordinates from the ecliptic inertial Cartesian system (that of items 2 through 10) into the non-rotating spin coordinate system (same reference as first system). The resulting matrix has a determinant of 1.0. The constituent elements are organized as: [11 12 13] [14 15 16] [17 18 19] Item 20: The roll angle is measure from the RIP direction (first point of Aries). Item 21: Sometimes the spin rate was lost (only zeros were returns). In this case, we have assumed the nominal spin rate of pi/6 rad/s, or 5rpm. The value in the data file remains 0.0. ........................................................................" /* DATA OBJECT DEFINITIONS */ OBJECT = HEADER_TABLE NAME = "ORBIT_ATTITUDE_HEADER" INTERCHANGE_FORMAT = BINARY ROW_BYTES = 97 COLUMNS = 15 ROWS = 1 ^STRUCTURE = "PVOAHEAD.FMT" END_OBJECT = HEADER_TABLE OBJECT = DATA_TABLE NAME = "ORBIT_ATTITUDE_DATA" INTERCHANGE_FORMAT = BINARY ROW_BYTES = 97 COLUMNS = 10 ROWS = 708 ^STRUCTURE = "PVOADATA.FMT" END_OBJECT = DATA_TABLE END