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

162 APPENDIX D. BAT SOFTWARE TOOL REFERENCE
maskwt Apply corrections for mask weighting technique
pcode Apply partial coding corrections
ndets Normalize by number of exposed detectors
subpixelate Use slower but potentially higher fidelity algorithm
forward Reserved for clean procedure
unbalanced Reserved for clean procedure
nearfield Near field corrections for ground calibration analysis only
• The “pcode” and “ndets” corrections require the user to supply the detmask
keyword.
(pcodethresh = 0.00) [real ]
Minimum allowable partial coding value allowed for the source position. This is a fraction
between 0.0 (no partial coding) and 1.0 (fully coded). For example, a value of 0.01 implies
that at least 1% of the detectors must be illuminated. Mask weights for events whose partial
coding is below the threshold will be set to zero.
(detmask = “NONE”) [string ]
Name of a detector quality map file. This should be an image file with the same dimensions
as the detector plane map. A pixel value of 0 indicates the detector is enabled, and a non-zero
value indicates disabled. A default value of NONE implies all detectors are on, except for the
BAT detector gap regions. This map is only used for computing the fraction of illuminated
pixels. The output mask weight map contains a value for all detectors in the array, regardless
of detmask.
(auxfile = “NONE”) [string ]
Specifies an auxiliary output file which describes the position of the source in the BAT
field of view as a function of time, including various ray tracing diagnostics. The columns
are TIME (MET in seconds); BAT X/Y/ZOBJ (source position in instrument coordinates
in cm); IMX/Y (source tangent plane coordinates); PCODEFR (partial coding fraction);
NGOODPIX (number of enabled detectors); MSKWTSQF (normalization parameter). One
row is created for each ray tracing operation performed. This file is required for response
matrix generation during slews.
(filtexpr = ”(EVENT FLAGS == 0) —— (EVENT FLAGS == 16)”) [string ]
Event filtering expression to be applied to the data. Any column filtering expression using
the columns or keywords in the event file is valid (see the help for the “colfilter” task for
more information). Events that fail the expression will have their mask weight set to zero.
The default expression rejects calibration and multi-hit events, which are never due to cosmic
sources. NOTE: users should not use spatial filters which exclude certain detectors, since
batmaskwtevt will be unable to properly normalize the weights. For spatial filtering, use a
detmask.
(bat z = 0) [real ]
Position of the source in BAT Z coordinates, if coord type is “cartesian” (in units of cm).
(maskwtcol = “MASK WEIGHT”) [string ]
Name of mask weight column.