CCSD3ZF0000100000001NJPL3IF0PDSX00000001 /* FILE: J0CD_EUV_G1NANS32.XLBL */ /* VERSION 1.4: 18-MAY-1999 MOSSER */ PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 4528 /*=1132*4 */ FILE_RECORDS = 2 PRODUCT_ID = "J0CD_EUV_G1NANS32.XDR" PRODUCT_NAME = "J0TUG1NANS32 EDR DATA" DATA_SET_ID = "GO-IT-EUV-2-EDR-IO_TORUS-V1.0" OBSERVATION_ID = "J0TUG1NANS32" SPACECRAFT_NAME = "GALILEO ORBITER" INSTRUMENT_NAME = "EXTREME UV SPECTROMETER" MISSION_PHASE_NAME = "JUPITER ORBIT OPERATIONS" TARGET_NAME = "IO-TORUS" PRODUCT_CREATION_TIME = "26-JUN-1996" START_TIME = 1996-174T22:44:59.132Z STOP_TIME = 1996-175T00:09:55.463Z SPACECRAFT_CLOCK_START_COUNT = "3491454:00:0" SPACECRAFT_CLOCK_STOP_COUNT = "3491538:00:0" ^SPECTRUM = "J0CD_EUV_G1NANS32.XDR" DESCRIPTION = " This file was produced by the Galileo UVS/EUV team at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado at Boulder. Refer to the Galileo UVS/EUV instrument paper 'Galileo Ultraviolet Spectrometer Experiment', Vol 60, Space Science Reviews, pages 503-530, by C.W. Hord et al, for hardware and calibration information and to the EUV Instrument template for a description of the Phase 2 (P2) data summation in the EUV internal buffer. The data contained in the file is IEEE XDR interchange format. MAY, 1999 The EUV data in this file were obtained using the EUV P2 RTS mode. Check the commanded configuration in the flight sequence for the most accurate understanding of these data. Calibration to physical units has not been made; the data are in units of 'raw counts per time'. The commanded instrument summation period, number of sky sectors and number of detector pixels summed are given in the command. The EUV integration time and sampling of the grating positions by use of a 'Fixed Pattern Noise Table' (FPNT) are described in the instrument template. Some command information is given in the engineering data embedded in the data portion of the record. The analysis of these raw data has not been published at this time. The data in this file was obtained using the TORUS FPN table. A diagram of the file and record structure is shown below: |-----+---------------| 1 |time | S | EUV RTS SUMMATION BUFFER |-----+---------------| . 2 |time | S | . |-----+---------------| . 3 |time | S | . |-----+---------------| . . . . repeats . . . |-----+---------------| . ij |time | S | EUV RTS SUMMATION BUFFER |-----+---------------| |40 4-| /S= \ |byte | /1092 \ |time | /4-byte \ |tags | /spectral \ |& hdr| / values \ Records 1 to ij are data records. Each record begins with a 160-byte header containing 40 4-byte integer numbers. The header values are described below, the exact definition of the time values is further described in the Galileo document 625-610. The time tags given in the data records refer to the time of the first integration period included in the packet summation period; the STOP time refers to the Rim time of the FLUSH command, which represents one Rim greater than the true summation period; these are derived from the EUV downlinked packets. The LABEL START and STOP time values refer to the FLUSH times as well. The data start at byte 161, following the header information. Each record contains one readout (termed FLUSH in the sequences) of the EUV Internal Buffer (EIB). The EIB contains the EUV sky-sector/pixel matrix summed over the Summation Period (an even number of Rims.) At the time of a FLUSH command, the CDS computer moves the buffer from the EUV microprocessor buffer to the downlink processing buffer, taking one full RIM to move the contents and send the EUV flag to zero it. The duration of the FLUSH periods is given by the data label start and stop times, and is generally one-half hour, one hour or 24 hours - minus the one RIM to transfer the data - but may be a subset of these. Each data record in the file can contain data from a different summation duration. Simply, the EUV samples areas of the sky, on each revolution, based on the command and the instrument integration time. The fixed EIB size is divided into sky-sectors by pixels. To utilize the space efficiently, the detector pixels are also summed over useful wavelengths; a table defining the pixel sums, FPNT, is loaded to the microprocessor each time the EUV is powered-On for the orbit data taking and is therefore available in the command sequence. For the P2 mission phase, there are three commonly used tables: TORUS, AURORA, and GENERAL. An EUV matrix has 24x45 data values followed by 24 housekeeping values. Some engineering operation (Temperature) values are available in the AACS records but are not included in the data records. The data matrix is arranged internally and read out so that the order of the matrix is: 1st value=(sector 1, lowest pixel sum), 2nd value= (sector 1, next pixel sum) so that all the pixels in one sector are read out before the next sector's pixels are placed into the downlink stream. They are, in order of presentation: 1 - fiducial, VALUE=7E (hex) 2 - fiducial, VALUE=7E (hex) 3 - TRANSITION SECTOR PAIR, MOD 64 - how many pixel pairs to ignore before starting integration 4 - COMMANDED PIXEL PAIR SUMS, - times 2, read from the FPNT 5 - echo of COMMANDED STARTING ANGLE - the value has unit size of (360.0 degrees/256.) 6 - echo of COMMANDED HIGH VOLTAGE LEVEL (always should be 3) 7 - echo of COMMANDED SCANS/SECTOR 8 - echo of COMMANDED SECTORS - may be changed by micro software 9 - NEXT TO LEAST SIGNIFICANT BYTE OF RIM COUNTER - prior to the beginning of the last integration 10 - LEAST SIGNIFICANT BYTE OF RIM COUNTER 11 - MOD91 OF RIM COUNTER ( = minor frame) 12 - MOD10 OF RIM COUNTER ( = RTI, Real Time Interrupt count) 13 - NEXT TO LEAST SIGNIFICANT BYTE OF DELTA THETA - Delta Theta is in units of degrees of sky in 66 2/3 msec (one RTI); the increment is 360/16,777,216 degrees.) 14 - LEAST SIGNIFICANT BYTE OF DELTA THETA 15 - MOST SIGNIFICANT BYTE OF THETA - Theta increment is 360/65,536 degrees. 16 - LEAST SIGNIFICANT BYTE OF THETA 17 - SOFTWARE VERSION NUMBER - P2 starts at 40 18 - MOST SIGNIFICANT BYTE OF 16-BIT INTEGRATION COUNTER 19 - LEAST SIGNIFICANT BYTE OF INTEGRATION COUNTER - this is the true number of revolutions (spins) EUV actually integrated 20 - EXACT CURRENT RTI - the actual value at time this is sampled; Values 15-19 pertain to the exact time 21 - TRANSITION SECTOR PAIR, MOD 200 22 - REAL TIME MINOR FRAME COUNTER - actual mf at this sample time 23 - SYNC COUNTER - the number of times the s/w has had to wait to sync up with the s/c time; expected value = 1 24 - spare up to 1080 values 24 values |-----------------------------------------|-----------| | one EUV summation matrix |engineering| All values in the EIB are summed, excluding the fiducials and engineering values. The 2-byte EIB rolls over and begins counting again from value zero. TORUS1:[GLL_RAW.INFO]EUV_PHASE2_RTS_HDR.DOC June 10, 1996 - Jeremy Gebben In phase 2 Real Time operations, the EUV instrument stores data in a 24 sector by 45 pixel matrix. Every few RIMs, this matrix and 24 bytes of housekeeping data are read out and cleared. These data sets are stored in IDL associate files formated as lonar(1132). HEADER: Earth Receipt Time 0 = Year (last 2 digits eg. 96) 1 = day of year 2 = hours 3 = minutes 4 = seconds 5 = milliseconds Spacecraft Event time for start of integration: 6 = Year (last 2 digits eg. 96) 7 = day of year 8 = hours 9 = minutes 10 = seconds 11 = milliseconds SCLK time for start of integration: 12 = start RIM (all realtime data starts on mf 0) Spacecraft Event time for end of integration: 13 = Year (last 2 digits eg. 96) 14 = day of year 15 = hours 16 = minutes 17 = seconds 18 = milliseconds SCLK time for end of integration: 19 = end RIM (all realtime data ends on mf 0) 20 = # of packets that went into this array(max = 8) Data presence Indicators: 21-28 = dpi flags,1 for each packet Each is a 4 byte field: Top byte: 00 = no data missing FF = entire packet missing 01 = data missing at end of packet 02 = data missing in middle of packet 03 = data missing at end of packet Lower 3 bytes are only used if the top byte is 01,02, or 03 In these cases, the three lower bytes are used to report the position of the gap: second byte: # of data words(2 bytes) at start(0 if gap is at start) third byte : # of data words missing bottom byte: # of data words at end of packet (0 if gap is at end) 29 = packet sequence # of the first packet in this set 30,31 = spare (set to -1) 32 = software version number 33-39 = spare (set to -1) DATA: 40-1119 = data matrix(24*45) all pixels from sector 1, then all pixels from sector 2 ... 1120-1131 = housekeeping values(2 bytes each) ........................................................" OBJECT = SPECTRUM NAME = "ONE EUV RTS SUMMATION BUFFER" INTERCHANGE_FORMAT = BINARY ROWS = 2 COLUMNS = 41 ROW_BYTES = 4528 ^STRUCTURE = "EUV_P2_RTS.FMT" DESCRIPTION = " The summation data table consists of 40 4-byte integers of time tags (RIM, yr, doy, hr, min, sec, etc), data quality flags and spares, and 1092 spectral values for one summed spectral pair. The record structure is the same as the table. " END_OBJECT = SPECTRUM END