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

140 APPENDIX D. BAT SOFTWARE TOOL REFERENCE
(bat z = 0) [real ]
For testing with a near-field source. The position of the source in centimeters along the
BAT Z axis. A value of 0 indicates infinity.
(origin z = 0) [real ]
For ground testing with a near-field source. The position of the origin of coordinates (in cm),
used for the angular measures attached to the output image.
(corrections = “default”) [string ]
Comma-separated list of corrections to apply to the image, or “none” if no corrections are to
be applied. The possible corrections are:
default Default corrections, which is shorthand for: ”autocollim,flatfield,maskwt,ndets,pcode”
autocollim Correct plate scale for autocollimation effect
flatfield Apply corrections for cosine and edge projection effects
maskwt Apply corrections for FFT technique
ndets Normalize by number of exposed detectors
pcode Apply partial coding corrections
(keepbits = “7”) [string ]
Integer number of bits of precision to keep in the output images. A value of ALL means
keep all bits. A positive value indicates that ‘keepbits’ bits of precision should be preserved,
and the other bits should be set to zero. Fewer kept bits means the output images are more
compressible, at the expense of lost precision. For partial coding maps and variance maps, a
straight number of bits are kept (thus preserving the same relative precision across the map).
For sky maps and significance maps, ‘keepbits’ prescribes the number ofnoise bits to keep;
more bits may be kept if a pixel is significantly above the noise (thus preserving the same
noise quantization error across the map). NOTE: it must be possible to compute a variance
map in order for most ‘keepbits’ operations to work. (see ‘bkgvarmap’ for restrictions).
(handedness = “left”) [string ]
The handedness of the image. For an image where north is up, a left-handed image has
East=left, and a right-handed image has East=right. “left” is conventional for astronomical
images.
(rows = “-”) [string ]
An index list of images to operate on. This is a standard comma-separated list of row ranges,
starting with image number 1. A range of “-” indicates all images should be processed.
(countscol = “INDEF”) [string ]
If the input image is a FITS table, the column to analyze. If countscol is INDEF, then the
first 2 dimensional column to be found in the table is used.
(teldef = “CALDB”) [string ]
BAT instrument telescope description file, which defines instrument-to-spacecraft alignments.
Must be specified in order to assign celestial coordinates to the output image. A value of
“NONE” disables celestial coordinates. By default the teldef file located in the HEADAS
reference data area is used. If the CALDB database is set up, then CALDB can also be
specified.