NAME

USAGE

DESCRIPTION

batwarpimg corrects BAT sky images for known imaging distortions. The distortion map is usually stored in the calibration database (CALDB), and describes the image shift in instrument coordinates. The input sky map is resampled with these slight shifts applied, so that sources appear at their "true" position.

Note that the interpolation process inherently involves some smoothing of the sky image, so a small amount of information is lost.

PARAMETERS

infile [filename]

The name (and optional extension) of the input image file name. If an explicit image extension name is supplied, and rows='-', then only that extension will be processed.

outfile [filename]

The name of the output image.

(rows = "-") [string]

List of images to be processed from the input file. The list must be comma-separated, and can have single elements or ranges. For example, "1,3-5,6". The first image in the file is number 1.

(distfile = "CALDB") [string]

Name of the distortion map, or CALDB if users have access to the BAT calibration database. This must be an N × M × 3 image extension with proper WCS keywords, including the alternate "T" coordinate system in tangent plane coordinates. The first image plane should be the (true-apparent) position offset in the IMX direction; the second plane is the same for the IMY direction.

(outcoord="TRUE") [string]

The output coordinate system. TRUE indicates to convert to "true" or corrected coordinates, while APPARENT indicates the reverse conversion. Note that because the conversion is lossy, a round trip pair of conversions may not equal the original.

(copyall="YES") [boolean]

Indicates whether to copy all other extensions. If yes, then the unprocessed extensions are copied untouched. If no, then only the processed extensions are saved.

(clobber = NO) [boolean]

If the output file already exists, then setting "clobber = yes" will cause it to be overwritten.

(chatter = 2) [integer, 0 - 5]

Controls the amount of informative text written to standard output. Setting chatter = 1 produces a basic summary of the task actions; chatter = 2 (default) additionally prints a summary of input parameters; chatter = 5 prints debugging information.

(history = YES) [boolean]

If history = YES, then a set of HISTORY keywords will be written to the header of the specified HDU in the output file to record the value of all the task parameters that were used to produce the output file.

EXAMPLES

1. Correct an image for distortions.

   batwarpimg input.fits output.fits distfile=CALDB

SEE ALSO

batfftimage

LAST MODIFIED