Apply a
matched filter to SCUBA-2 images with the aim of enhancing point sources. The given images are
convolved with a PSF, which the user can supply or is created by the recipe. Before the convolution,
the maps and the PSF are smoothed with a gaussian, and these smoothed versions are subtracted from
the unsmoothed versions.
The default PSF is a two-component gaussian model of the JCMT beam with relative amplitudes and
FWHM as given in the SCUBA-2 calibration paper (Mairs et al. 2021, AJ, 162, 191).
The following parameters can be set via the -recpars
option:
KEEPFILES
A flag to indicate that the PSF created by this recipe should remain on disk
after processing. If not specified, the PSF will be deleted if one is created. This parameter is ignored if a
PSF file is given (see PSF_MATCHFILTER).
PSF_MATCHFILTER
Name of an NDF file containing a
suitable PSF. Must exist in the current working directory. If not specified, the recipe will calculate one
itself for each input file.
PSF_NORM
Normalization scheme used for the PSF created
by this recipe if one is not specified using the above parameter. Maybe be PEAK or SUM
to indicate whether the Gaussian PSF should have a peak of unity or a sum of unity. If
not specified, the recipe assumes PEAK.
SMOOTH_DATA
Flag to denote whether or
not the image and PSF should be smoothed and have the smoothed version subtracted
from the original. If not specified, the recipe assumes a value of 1 (smooth and subtract).
SMOOTH_FWHM
FWHM of Gaussian used to smooth data and PSF images before
convolving with the PSF. If not specified the recipe assumes 30 arcsec.