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

D.9. BATGLOBALGTI 143
D.9 BATGLOBALGTI
D.9.1 NAME
batglobalgti - retrieve BAT global science analysis times
D.9.2 USAGE
batglobalgti infile outfile
D.9.3 DESCRIPTION
batglobalgti retrieves global good or bad times for BAT science analysis. The BAT CALDB has a
GTI file which contains a listing of all known good and bad science analysis times, include a quality
indicator and a description of any issues. This GTI is meant to reflect any operational issues that
affected the BAT science data quality which are not easily extractable from the filter file or other
telemetry. The user is not excused from doing other routine quality filtering, for example for SAA
or noisy detectors. Thus, this task is most useful for doing gross filtering of data at the observation
level to remove times of known bad data.
The time intervals stored in the GTI file have QUALITY values assigned according to the
following scale:
0 No known issues; data OK
1 Something non-routine occurred, but it had no known impact;
2 Bad data, with some possible good data; user must proceed with extreme caution;
3 Bad data, with little to no good data.
The user can choose which quality level to accept with the ‘expr’ parameter. The default value
is 0 or 1.
The result is a standard GTI file that can be merged with other GTI files, or otherwise used to
time filter time-ordered Swift data. This GTI file applies to the entire mission duration.
Please note: The time intervals in the output file are not necessarily “good.” That depends
on the quality level chosen (i.e. if one chooses expr=”QUALITY >= 2” then only the bad time
intervals will be selected).
D.9.4 PARAMETERS
infile [filename ]
Global good/bad science time interval file. A value of “CALDB” is allowed (and in fact
recommended), indicating to select data from the Calibration database.