PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2000-06-13 NOTE = " GRB Data File Parameter Definitions " END_OBJECT = TEXT END GAMMA RAY BURST SCIENCE RECORD VARIABLES (Binary Table Fields) The following list of variable names are contained in the header of the Binary table extension of the gamma ray burst data file created by CFITSIO user routines for PDS compliance. The corresponding definitions will be placed in a separate file, and will not be contained in the PDS label file, or require the generation of PDS keywords. 1. met minimum value - 0 maximum value - 2**32-1 (4294967295) units - seconds (unsigned) definition - Mission Elapsed Time in seconds for the start of this NIS integration period 2. tdb minimum value - -1.7976931348623157e+308 maximum value - +1.7976931348623157e+308 units - seconds (signed) definition - Barycentric Dynamical Time corresponding to MET(1). Barycentric Dynamical Time (TDB) is the independent variable in the equations, including terms for relativity, of motion of the celestial bodies. The solution of these equations gives the rectangular coordinates of those bodies relative to the barycentre (centre of mass) of the solar system. (The barycentre does not coincide with the centre of the Sun but is displaced to a point near its surface in the direction of Jupiter.) 3. dqi minimum value - N/A maximum value - N/A units - N/A definition - Data Quality Index c0 = Data Quality Flag[0=good,1=flagged for quality defects] c1 = Instrument number for FC, CTP and AIU[1 or 2] c2 - c6 = File Specific c7 = CCDS Source[0=VC0, 1=VC1, 2=VC2, 3=VC3] 4. sample_start_met minimum value - 0 maximum value - 2**32-1 units - seconds definition - Burst data start MET - start time in seconds for collection of 1st one second burst counter sample 5. gamma_thresh_var minimum value - 0 maximum value - 1023 units - N/A definition - Burst high energy threshold - determines how one second gamma ray burst counter samples are formed; if burst threshold = 0, one second samples are taken from the BGO raw hardware event counter; if burst threshold between 1and 1023, the one second samples correspond the number of BGO events in each one second period whose energy bins fall between 0 and the burst high energy threshold. initial value: energy bin 100 6. xray_integ_start_met minimum value - 0 maximum value - 2**32-1 units - seconds definition - Crosstalk start MET - start time in seconds of the Xray record period over which the crosstalk counter included in this record was accumulated 7. crosstalk_counter minimum value - 0 maximum value - 65,535 units - N/A definition - Crosstalk counter - a count of the high energy gamma ray events which occurred over an entire record period for the most recently completed Xray period (independent of gamma ray sensor masking); individual anti-coincident high energy gamma ray events each cause this counter to be incremented by 1; coincident gamma ray events cause this counter to be incremented by 1 if either or both are high energy; each time the counter is incremented, the three primary Xray sensor channels (unfiltered, Mg, and Al) are cleared of any pending events by the XGRS software 8. encoded_crosstalk_thresh minimum value - N/A maximum value - N/A units - N/A definition - Encoded crosstalk thresholds - an encoding of the thresholds which are used in determining "high energy" gamma ray events in the context of crosstalk processing; events whose energy bins exceed this threshold will be considered high energy (for the purposes of crosstalk processing only) ground conversion: encoded thr 1022 or 2222 = NaI and BGO crosstalk thr both 1022 encoded thr 2223 = NaI crosstalk thr 1022; BGO crosstalk thr 1023 encoded thr 2322 = NaI crosstalk thr 1023; BGO crosstalk thr 1022 encoded thr 2323 = NaI and BGO crosstalk thr both 1023 Note: a crosstalk threshold of 1023 effectively disables crosstalk processing for that sensor, since only events in energy bin > 1023 (none) would be considered high energy; a crosstalk threshold of 1022 enables crosstalk processing for that sensor with high energy bins considered to be energy bin 1023 only. initial value: energy bin 1022 9. gamma_burst_mode[GAMMA_BURST_DIMS] minimum value - 0 maximum value - 2**16-1 units - N/A definition - gamma ray burst counter samples - 166 16-bit unsigned words; each word represents a one second counter sample (of either the BGO raw hw ctr or the sum of events in energy bins 0 to the burst thr for that one second) -------------------------------------------------------------------------- ------ NEAR KEYWORDS and Examples The following list of NEAR keywords reflects the current status and can be modified as required. NEAR-001= 5760 / 012 Data offset from start of file (bytes) NEAR-002= '1.01 ' / Version of this file format NEAR-003= 'GRB98037.FIT' / Name of this file NEAR-004= '01:41:57Z' / Time that this file was created NEAR-005= 'GRB.001 ' / Product ID NEAR-006= 'PDSGRB ' / Program name that produced this file NEAR-007= ' ' / Version # of above program COMMENT NEAR Project Parameters Can Have Names NEAR-001 Through NEAR-099 NEAR-601= 'XGR ' / File Type NEAR-602= ' ' / Scaling File NEAR-603= ' ' / Version of Scaling File NEAR-604= 62133424 / 024 Initial MET in File NEAR-605= 62188036 / 025 Final MET in File NEAR-606= 'GAMMABURST' / Instrument type NEAR-607= 'xgrs.c ' / Program name produced input file NEAR-608= '1.9 ' / Version of above program COMMENT Additional Science Team Defined Parameters Below NEAR-609= ' ' / Spare NEAR-610= ' ' / Spare NEAR-611= ' ' / Spare NEAR-612= ' ' / Spare COMMENT Lines Before The Last Can Be Used For Documentation COMMENT