NAME

sampcum -- accumulate a MultiAccum image from a set of first differences

USAGE

sampcum image outimage zeroimage template

DESCRIPTION

Sampcum is a CL script that sums a series of first differences in a NICMOS MultiAccum file into a normal set of accumulating SCI image extensions. The output file is initially created as a copy of the template file. Next, the zero read SCI image extension in the output file is replaced by the image referenced by the "zeroimage" parameter. Then the remaining SCI image extensions in the output file are replaced by the accumulating sums of the input file SCI image extensions, starting with the first read (IMSET = NSAMP-1) and proceeding through to the last read (IMSET = 1).

The corresponding task "sampdiff" can be used to create first differences.

PARAMETERS

image [file]

Input image. The full file name must be given. Normally this is a NICMOS _ima.fits file.

outimage [file]

Output image name. The full file name must be given. This file will have the same structure and number of IMSETs as the input file.

zeroimage [file]

Image to use for zero read of output image. The zero read SCI image extension of the input image may be used. A full image extension specification must be provided if the image is contained in a multi-extension FITS file.

template [file]

Image to use as a template for the output image. The output image is initially created as an exact copy of the template image, and the SCI image extensions are subsequently updated with the accumulated data. The input image may be used as the template.

EXAMPLES

1. Reaccumulate the first differences in the file "n4xj13jwq_fdiff.fits", storing the results in file "n4xj13jqd_reacc.fits". The original IMA file for this dataset, "n4xj13jwq_ima.fits", is used as the template, and the zero read SCI image extension from this file is used for the zero read of the output file.

 cl> sampcum n4xj13jwq_fdiff.fits n4xj13jwq_reacc.fits \
 >>> n4xj13jwq_ima[sci,12] n4xj13jwq_ima.fits

BUGS

REFERENCES

Authors: M. Dickinson, H. Bushouse, STScI

SEE ALSO

sampdiff