• SCUBA2_MATCHED_FILTER

SCUBA2_MATCHED_FILTER

Description

Apply a matched filter to the data to improve point-source detectability. The images and PSFs are smoothed with a broad Gaussian (default is 20/30 arcsec at 450/850 um, but can be varied using the recipe parameter below) and subtracted from the originals. The images are convolved with the modified PSFs. The PSF created by the recipe is a Gaussian with FWHM equal to the JCMT beamsize at the appropriate wavelength (i.e. 7.5 or 14 arcsec).

Creates an output file for each input file with the suffix "_mf", and a PSF file "_psf" if the PSF was not specified as a recipe parameter.

Notes

Note the data and PSF images will be smoothed and subtracted from the originals unless otherwise specified.

Available recipe parameters

• PSF_MATCHFILTER
  • name of a PSF file (NDF format, will be used for all images)
• PSF_NORM
  • switch to determine whether a PSF is normalized to a peak of unity ("peak" - the default) or a sum of unity ("sum")
• SMOOTH_DATA
  • switch to determine whether or not the data and PSF images are smoothed and subtracted before convolving (default is to smooth and subtract, so set to 0 if that is not wanted)
• SMOOTH_FWHM
  • FWHM in arcsec of Gaussian to smooth image (and PSF)