The SWIFT BAT Software Guide Version 6.3 30 ... - HEASARC - Nasa

74 APPENDIX A. BAT DATA FORMATS
A.5.6 TDRSS GRB Light Curves
Burst light curves (code “msb” or “bhp”) are sent down in two channels, through TDRSS and in
the high priority solid-state recorder ground pass channel. These files cover a time from 24 seconds
before to 185 seconds after the burst. They have four energy channels. The time binning varies
and is densest (0.128 seconds) closest to the trigger time and least dense (4.096 seconds) well after
the trigger. Since these light curves come through the TDRSS channel they can be used to quickly
determine high level burst properties. The TDRSS light curves also have attitude data attached
on the same time scale as the light curves. The attitude data is processed into separate files.
Layout. Initial BAT TDRSS light curve EXTNAME = ‘TDRSS LC’
Name Format [Units] Comment
TIME 1D [s] TIME of rates
RELTIME 1D [s] Bin time relative to trigger time
TIMEDEL 1D [s] Width of time bin
RAW COUNTS 4J [count] Counts per time bin in 4 energy bins
RATE 4E [count/s] Rate in 4 energy bins
ERROR 4E [count/s] Statistical uncertainty in RATE
TOT COUNTS 1J [count] Total array counts in all energy bins
TOT RATE 1E [count/s] Total array rate in all energy bins
TOT RATE ERR 1E [count/s] Statistical uncertainty in TOT RATE
A.6 Maps
A.6.1 Detector Enable/Disable Map
Detector enable/disable maps (code “decb”). The BAT on-board software automatically maintains
a map of enabled and disabled detectors. Detectors may be automatically disabled if they are noisy.
Detectors may also be enabled or disabled based on ground command. When the enable/disable
state changes, a new map is set to the ground. NOTE: per OGIP convention, a 0 value indicates
an enabled detector, while a non-zero value indicates a disabled detector.
Detector enable/disable maps are not always produced during every observation, but the Swift
Data Center should collect the nearest map for each snapshot, and should include these maps in
the “decb” file.
Layout. Detector Enable/Disable Map EXTNAME = ‘Det Enable Map’
Name Format [Units] Comment
TIME 1D [s] TIME associated with Detector Enable
FLAG (286,173)B Detector logical flag 0=enabled, 1=disabled
DATA FLAGS 1I Data Quality 0=OK, 1=Problem
LDPNAME 240A15 BAT File Name
BLOCK MAP 1I Block Bit Mask
NUM DETS 1J Number of detectors
APID 1I Application Process Identifier
LDP 1J LDP Product Number