PDS_VERSION_ID = PDS3 /* FILE: BPER::USER05:[FREUND]MM1145K.LBL */ /* VERSION 1.0: Wed Nov 8 22:46:17 2000 SIMMONS */ /* UPDATE TO DAS END TIMES MAY 20,2012 SAINSBURY */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 5060 /*=intarr(1265) */ FILE_RECORDS = 3215 PRODUCT_ID = "MM1145K.XDR" PRODUCT_NAME = "MARINER 1971 ORBITAL DATA" DATA_SET_ID = "MR9-M-UVS-2-EDR-V1.0" SPACECRAFT_NAME = "MARINER 9 ORBITER" INSTRUMENT_NAME = "ULTRAVIOLET SPECTROMETER" TARGET_NAME = "MARS" PRODUCT_CREATION_TIME = 1986-10-31 START_TIME = 1972-025T10:52:33.70Z STOP_TIME = 1972-026T04:12:33.20Z SPACECRAFT_CLOCK_START_COUNT = "6781046" SPACECRAFT_CLOCK_STOP_COUNT = "6825416" ^SPECTRUM ="MM1145K.XDR" DESCRIPTION = " This file was produced by the Mariner 9 (MM71 and M9) Ultraviolet Spectrometer (UVS) team at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado at Boulder. The UVS Principle Investigator (PI) was Dr. Charles A. Barth. Refer to the Mariner 1971 UVS instrument paper 'Ultraviolet Spectrometer Experiment', Vol 60, Space Science Reviews, pages 503-530, by C.W. Hord et al, for hardware and calibration information. See the Instrument template and the Publication references for additional information. A diagram of the file and record structure is shown below: |-----+---------------+----------------| 0 |time |G-chan Fid&spec|F-chan Fid&spec | SPECTRUM |-----+---------------|----------------| . 1 |time | same |F-chan Fid&spec | . |-----+---------------+----------------| . 2 |time | same |F-chan Fid&spec | . |-----+---------------+----------------| . . . . . repeats . . . . . |-----+---------------+----------------| . ij |time | same |F-chan Fid&spec | SPECTRUM |-----+---------------+----------------| |55 4-| / G \ / F \ |byte | / 605 \ / 605 \ |time | /4-byte \ / 4-byte \ |or | /spectrum \ /spectrum \ |flags| Records 0 to ij are data records. Each record begins with a 55 4-byte header containing JPL identifications, several time tags and spare words. Each spectrum consists of 72 fiducial/housekeeping values, 528 spectral readouts and 5 spare words (for a total of 605 values). These IEEE standard interchange format files (called filename.XDR) contain 4-byte integers the top two bytes of which are actually all zeroes. The IDL Vax (filename.DAT) and IDL Unix (filename.UDAT) files contain 2-byte integer 'Associate' records. This document describes the .XDR files. Note: many of the values are coded in octal, especially the time tags, so if you do not understand a decimal value, try converting it to octal and possibly using it as an integer multiplication factor or integer digit holder. (8D stands for 8 Decimal and 10O stands for 10 Octal.) Item Contents 0 Instrument ID: should be 8D or 10O for UVS 1 Spacecraft ID: should be 5D for second spacecraft (ie, M9) 2 Data rate and format: 394D=612O for 16.2 Kbps and f/t 10 or 12O 3 Data Source Rate and Gain State (from F-chan fid,value 66); DS: 00=8.33 bps, 33.33, 1.1025, 2.025, 4.05, 8.10, 16.2, 50.0 GS nominal = 1 4 Station Number (11,12,13,14,41,42,43,51,61,62,63) 5 spare 6 spare 7 spare 8 DAS (Data Automation System) clock, upper bits 9 DAS clock lower bits; time=(DAS Upper*4096.)+DAS Lower The DAS unit is 2.5 seconds 10 ? 11 Record number 12 spare 13 spare Spacecraft Event Time in GMT WARNING: all time values are octally coded; a '10Oct' =9Dec 14 Year,Day of year: (one digit Year,one digit of 100s of Days) (add the yr digit to 1971; ie 0=1971) 15 Day of Year: (upper digit for 10s of Days, lower two for ones) 16 Hour 17 Minutes: (upper digits for 10s of Minutes, lower digits for ones) 18 Seconds: (upper digits for 10s of Seconds, lower digits for ones) 19 Decimal Seconds: (upper digits of Tenths of Seconds, lower two for Hundredths of Seconds) 20-25.5 Flags | 25.5-27 Spares |Note: another document says 24-29 is Earth Receipt 28-29 ? | Time in BCD 30-32 Telemetry Signal To Noise 33-34 ? Orbit (appears to be empty) 35-39 ? Time to Periapsis (appears to be empty) 34-54 Spares 55-126 G-channel Fiducial (See table below) 127-654 G-channel 528 spectral data 655-650 spare 660-731 F-channel Fiducial (See table below) 732-1259 F-channel 528 spectral data 1260-1264 spare FIDUCIALS The sensitivity of the F-channel was controlled by a count sampling technique which would decrease the sensitivity on the next spectrum if the count rates exceeded the 255 data counter maximum. This 'Gain State' level is registered in the engineering fiducial. (See the Fiducial table below and the MMRD.PRO software.) The G and F-channel fiducials measure several engineering values. The table below is taken from John Farrar's Technical Memorandum 33-569. It references five different measurements contained in the fiducials of the G and F-channel spectra. (He refers to these as 'steps'.) Step Duration, ms G-channel value F-channel value A 160 Zero Check Zero Check B 110 Gain Calibration Gain Calibration C 65 Temperature T1 Temperature T2 D 20 15V Monitor Gain Indicator E 20 High Voltage High Voltage The following values are then given (DN are Data Numbers, 255=Max): FUNCTION RANGE in DN TEMP.(deg C) HI.VOLTAGE Measured on UVS-2 (M9) Zero Check 4 (+,- 2) Gain Calibration 185 (+,- 3) Temperature T2 108 (+,- 2) -20 128 2 -10 147 2 0 165 2 10 179 2 20 189 2 30 200 2 40 Gain Indicator 0 30 2 -1076 NOTE:see 1 56 2 -1270 QUALITY 2 85 2 -1499 below 3 111 2 -1731 4 137 3 -2009 5 163 2 -2312 6 189 2 -2672 7 215 2 -3126 Hi Voltage Mon 0 70 2 -1076 1 81 2 -1270 2 92 2 -1499 3 104 2 -1731 4 119 2 -2009 5 135 2 -2312 6 153 2 -2672 7 176 2 -3126 Measured on UVS-1 (M8) Temperature T1 106 2 -20 130 2 -10 151 2 0 172 2 10 187 2 20 200 2 30 208 2 40 15V Monitor 206 2 There are 72 values in each fiducial preceeding the spectral data. It is suggested the user verify the shape of the fuducial before blindly applying a positional value in order to verify that the fiducial has not shifted from its normal record position. There appears to have been extra words in the G-channel telemetry data for some unknown reason which may have caused the F-channel fiducial and spectrum to be shifted. This applies to the wavelength deter- mination as well; see the description in the QUALITY section. SOFTWARE The record format of the MMxxxxj.XDR files is IEEE 4-byte integer interchange format sequential records. The MMxxxxj.DAT files are Vax formated, IDL 'Associate' 2-byte integer files; the MMxxxxj.UDAT are Sun OS Unix IDL 'Associate' 2-byte integer files. An IDL program to read the data files is given in MMRD.PRO, located in the software directory. It applies to the IDL Associate formatted files. There are also two IDL 'Structure' files for the UVS EDR and SEDR records. QUALITY The spacecraft telemetry records occasionally contained more that 528 words for a spectrum, especially in the G-channel position. The PI always located a spectral feature in order adjust the wavelength position correctly. The grating drive is known to have suffered wear, shifting the wavelength by up to three positions by the end of the mapping orbits (orbit 216). DAS time values were occasionally missing from the telemetry records. The 'K' file versions (of the MMxxxxK.DAT) edited in these missing values. Any value of 'j' not equal to 'K' represents an additional edit of the files (for undocumented reasons.) The extended mission orbit files (beyond orbit 216) do not contain DAS edited values. Immediately after data was available, Dr. Barth corrected the Gain State multiplication values based on (flight) stellar calibration data and other factors. The MMRD program has the updated Gain State values as given below. The user should average the four Gain State monitor values and find the closest factor in this table. Gain State DN Multiply the raw F-channel counts by 30 2154. 56 624.35 81 185.25 107 59.19 137 20.48 162 7.64 187 2.81 215 1.04 ............................................................" OBJECT = SPECTRUM INTERCHANGE_FORMAT = BINARY RECORDS = 3215 COLUMNS = 56 ROW_BYTES = 5060. ^STRUCTURE = "M9UVSEDR.FMT" DESCRIPTION = " A file containing UVS spectra from the Mariner 71 orbiter. Each record contains time tags with G-channel and F-channel spectra. Instrument housekeeping fiducials preceeding each spectrum." END_OBJECT = SPECTRUM END