Create a scaled PSF from maps with fake sources added SCUBA2_JACKKNIFE_PSF
The input files should be those created by a call to the SCUBA-2 pipeline recipe REDUCE_SCAN_FAINT_POINT_SOURCES_JACKKNIFE (or one of its aliases) that have had the artificial gaussian added at the map-making stage. These will have a suffix of _mappsf.
The PSF is scaled using a factor read from the FITS headers of the input files if available, or from a recipe parameter (see below).
This PSF may then be given to SCUBA2_JACKKNIFE via the recipe parameter PSF_MATCHFILTER.
Care should be taken to use the (_mappsf) files that correspond to the signal maps.
The output PSF has suffix _effpsf.
To ensure consistency, the PSF scaling factor in the FITS header takes precedence over a value derived from any given recipe parameters.