Parameters

 Keyword  Position  Type       Description
 -------  --------  ----       -----------
 GAUSS       -      LOGICAL    Use Gaussian (or Box)filter.
      Default = YES
 XWID        1      REAL       FWHM or box width in x (pixels).
      Default = 1.0
 YWID        2      REAL       FWHM or box width in y (pixels).
      Default = 1.0