PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = " 2011-04-23 DI:Carcich Created table 2013-02-08 EPOXI:McLaughlin Added DSIDs Doc Set V4.0. " NOTE = "SCLK corrections for Deep Impact encounter with 9P/Tempel 1 observations taken within ~3h of the spacecraft closest approach" RECORD_TYPE = "FIXED_LENGTH" RECORD_BYTES = 157 FILE_RECORDS = 1719 ^TABLE = "SCLK_FIX_DI.TAB" DATA_SET_ID = { "DIF-C-HRII-2-9P-ENCOUNTER-V1.0" , "DIF-C-HRIV-2-9P-ENCOUNTER-V1.0" , "DIF-C-MRI-2-9P-ENCOUNTER-V1.0" , "DII-C-ITS-2-9P-ENCOUNTER-V1.0" , "DIF-C-HRII-3/4-9P-ENCOUNTER-V1.0" , "DIF-C-HRIV-3/4-9P-ENCOUNTER-V1.0" , "DIF-C-MRI-3/4-9P-ENCOUNTER-V1.0" , "DII-C-ITS-3/4-9P-ENCOUNTER-V1.0" , "DIF-C-HRII-3/4-9P-ENCOUNTER-V2.0" , "DIF-C-HRIV-3/4-9P-ENCOUNTER-V2.0" , "DIF-C-MRI-3/4-9P-ENCOUNTER-V2.0" , "DII-C-ITS-3/4-9P-ENCOUNTER-V2.0" , "DIF-C-HRIV-2-NAV-9P-ENCOUNTER-V1.0" , "DIF-C-MRI-2-NAV-9P-ENCOUNTER-V1.1" , "DII-C-ITS-2-NAV-9P-ENCOUNTER-V1.1" , "DIF-C-HRIV-3-NAV-9P-ENCOUNTER-V1.0" , "DIF-C-MRI-3-NAV-9P-ENCOUNTER-V1.1" , "DII-C-ITS-3-NAV-9P-ENCOUNTER-V1.0" , "DI-C-HRII/HRIV/MRI/ITS-6-DOC-SET-V4.0" } PRODUCT_NAME = "DI 9P ENCOUNTER SCLK CORRECTION TABLE" PRODUCT_ID = "DI9P_SCLK_CORRECTION_TABLE" INSTRUMENT_HOST_NAME = { "DEEP IMPACT FLYBY SPACECRAFT" , "DEEP IMPACT IMPACTOR SPACECRAFT" } INSTRUMENT_NAME = { "DEEP IMPACT HIGH RESOLUTION INSTRUMENT - IR SPECTROMETER" , "DEEP IMPACT HIGH RESOLUTION INSTRUMENT - VISIBLE CCD" , "DEEP IMPACT MEDIUM RESOLUTION INSTRUMENT - VISIBLE CCD" , "DEEP IMPACT IMPACTOR TARGETING SENSOR - VISIBLE CCD" } TARGET_NAME = "9P/TEMPEL 1 (1867 G1)" START_TIME = 2005-07-04T02:44:00 STOP_TIME = 2005-07-09T08:45:00 PRODUCT_CREATION_TIME = 2011-04-23T00:00:00 OBJECT = TABLE INTERCHANGE_FORMAT = "ASCII" NAME = "DI9P_SCLK_CORRECTION_TABLE" ROWS = 1719 ROW_BYTES = 157 COLUMNS = 10 DESCRIPTION = "This table contains information that may be used to correct spacecraft clock (SCLK) times in Deep Impact 9P/Tempel 1 encounter data, which times were incorrectly determined from the raw spacecraft files in DI 9P encounter PDS datasets specified by the DATA_SET_ID keyword above. This table covers observations from all DI instruments. The details of the correction may be found in the documentation delivered with this table; see PDS label SCLK_FIX_DI.LBL and text document SCLK_FIX.ASC, both of which should be in the same directory as this table, ideally /SCLK_FIX/. In brief, there were two errors made converting the base timestamp in the spacecraft files (CODMAC Level 1) to the times in the archived data products: the modulus of the sub-second (subtick) counter was assumed to be 65,536 instead of the actual value of 62,500; the base timestamp was assumed to apply to the end of the exposure for all instruments and all instrument modes when that is not the case for HRI IR data taken in Modes 5 (ALTFF) and 6 (DIAG). The magnitude of the base timestamp correction is never more than about 40 ms; it is smallest at the start of each spacecraft clock second and largest at the end of each second. Because this correction is so small, only observations taken within three hours of the closest approach time of the DI spacecraft to 9P/Tempel 1 have been listed in this table. The correction in start and stop times will be bigger by the observation EXPOSURE_DURATION time for HRI IR data taken in ALTFF or DIAG instrument modes, but this table contains no such data. This table does not provide a correction for the UTC times (START_TIME, STOP_TIME, and others) for each observation, nor does it provide a correction for the trajectory and attitude (pointing) ephemeris for each observation. However it does provide the previous base timestamp and mid-observation spacecraft clock values for comparison so a determination could be made whether such corrections would be needed. Each row refers to one observation from one of the instruments and for that observation lists the unique part of the PRODUCT_ID, the value in seconds of the correction from old to corrected SCLK, the instrument mode, the corrected start-, mid- and end-observation spacecraft clock strings, the corrected base timestamp, the uncorrected base timestamp, the uncorrected mid-observation timestamp, and a YES or NO value indicating whether the mid-observation spacecraft clock value has changed. See the description of each column for more details. Each row of the table is terminated with a carriage return and a line feed. The fields are separated by commands so this table may be easily imported into a spreadsheet application. Each column field is constant-width and enclosed in double quote characters. " OBJECT = COLUMN COLUMN_NUMBER = 1 NAME = "PRODID_PREFIX" START_BYTE = 2 BYTES = 24 DATA_TYPE = "CHARACTER" FORMAT = "A24" DESCRIPTION = "This field is the unique start to the original PRODUCT_ID for the observation. The string '_FIT', when added to this field, will create the PRODUCT_ID for the raw (CODMAC Level 2) data product; the strings '_RR_FIT' and '_R_FIT' will create the PRODUCT_IDs for the calibrated (CODMAC Level 3) RAD and RADREV data products. The first two characters of this field indicate from which instrument the observation was taken: HI is HRI IR; HV is HRI VIS; IV is ITS; MV is MRI VIS" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME = "CORRECTION_S" START_BYTE = 28 BYTES = 8 DATA_TYPE = "ASCII_REAL" FORMAT = "F8.3" UNIT = "s" DESCRIPTION = "This field is the difference, in units of seconds, of the correction for the mid-observation spacecraft clock (SCLK) value for the observation. This value is calculated by converting the corrected SCLK string (column SPACECRAFT_CLOCK_MID_COUNT in this table) and the old SCLK string (column SPACECRAFT_CLOCK_MID_COUNT_OLD in this table) to decimal fraction seconds, and then subtracting the old value from the new value. Note that this value is based on the original and corrected SCLK values which have a resolution of ~4ms, and that in some cases the correction is zero." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME = "INSTRUMENT_MODE_NAME" START_BYTE = 38 BYTES = 5 DATA_TYPE = "CHARACTER" FORMAT = "A5" DESCRIPTION = "This field is the instrument mode name for the observation. This field is only included to determine whether the base timestamp occurs at the end of the observation or at the start. See the table DESCRIPTION for more detail." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME = "SPACECRAFT_CLOCK_START_COUNT" START_BYTE = 46 BYTES = 14 DATA_TYPE = "CHARACTER" FORMAT = "A14" DESCRIPTION = "This field is the SPICE SCLK (spacecraft clock) for this observation, at the start of the observation. The accuracy is about 4ms. The partition is not included but would always be 1. See the SPICE SCLK-Kernel and the SPICE toolkit for converting this time to a UTC." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME = "SPACECRAFT_CLOCK_MID_COUNT" START_BYTE = 63 BYTES = 14 DATA_TYPE = "CHARACTER" FORMAT = "A14" DESCRIPTION = "This field is the SPICE SCLK (spacecraft clock) for this observation, at the middle of the observation. The accuracy is about 4ms. The partition is not included but would always be 1. See the SPICE SCLK-Kernel and the SPICE toolkit for converting this time to a UTC." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME = "SPACECRAFT_CLOCK_STOP_COUNT" START_BYTE = 80 BYTES = 14 DATA_TYPE = "CHARACTER" FORMAT = "A14" DESCRIPTION = "This field is the SPICE SCLK (spacecraft clock) for this observation, at the end of the observation. The accuracy is about 4ms. The partition is not included but would always be 1. See the SPICE SCLK-Kernel and the SPICE toolkit for converting this time to a UTC." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 7 NAME = "SPACECRAFT_CLOCK_BASE_COUNT" START_BYTE = 97 BYTES = 14 DATA_TYPE = "CHARACTER" FORMAT = "A14" DESCRIPTION = "This field is the SPICE SCLK (spacecraft clock) for this observation, at the base timestamp of the observation. For all but HRI IR Mode 5 (ALTFF) and 6 (DIAG) data this will be the same as the end SCLK; for those other modes named this will be the same as the start SCLK. The accuracy is about 4ms. The partition is not included but would always be 1. See the SPICE SCLK-Kernel and the SPICE toolkit for converting this time to a UTC." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 8 NAME = "SPACECRAFT_CLOCK_BASE_COUNT_OLD" START_BYTE = 114 BYTES = 16 DATA_TYPE = "CHARACTER" FORMAT = "A16" DESCRIPTION = "This field is the incorrect SPICE SCLK (spacecraft clock) of the base timestamp of the observation from the previous version. It is only here to compare with the corrected base timestamp of the observation." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 9 NAME = "SPACECRAFT_CLOCK_MID_COUNT_OLD" START_BYTE = 133 BYTES = 16 DATA_TYPE = "CHARACTER" FORMAT = "A16" DESCRIPTION = "This field is the incorrect SPICE SCLK (spacecraft clock) of the mid-observation time of the observation from the previous version. It is only here to compare with the corrected mid-observation time of the observation." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 10 NAME = "SPACECRAFT_CLOCK_MID_COUNT_OLD" START_BYTE = 152 BYTES = 3 DATA_TYPE = "CHARACTER" FORMAT = "A3" DESCRIPTION = "This field indicates whether the 10-digit seconds portion of the mid-observation time of the observation changed as a result of the correction. The value will be 'YES' if it did change or 'NO ' if did not. The reason for this field is that the PRODUCT_ID contains the seconds field noted, and if the data pipeline ever re-runs these data with the timing correction, then the PRODUCT_ID for the observation may change." END_OBJECT = COLUMN END_OBJECT = TABLE END