If positions in the ARD description are given using a co-ordinate system that has one fewer axes than the input NDF, then each line or plane in the NDF will be masked independently using the supplied ARD description. For instance, if a two-dimensional ARD description that uses (RA,Dec) to specify positions is used to mask a three-dimensional (ra,dec,velocity) NDF, then each velocity plane in the NDF will be masked independently.
"COFRAME(SKY,System=FK5)"would indicate that positions are specified in RA/DEC (FK5,J2000). The statement
"COFRAME(PIXEL)"indicates explicitly that positions are specified in pixel co-ordinates.
"Error"is equivalent to
TRUEvalue is supplied for DEFPIX, then co-ordinates in the supplied ARD file will be assumed to be pixel co-ordinates. Otherwise, they are assumed to be in the current WCS co-ordinate system of the supplied NDF.
TRUEvalue is supplied, the constant value is assigned to the inside of the region specified by the ARD file. Otherwise, it is assigned to the outside.
!) propagates the title from the input NDF to the output NDF.
"A1060 galaxies masked". This might be to flag the pixels where bright galaxies are located to exclude them from sky-background fitting.
ardfile.txtto the bad value. The resultant image is output to the NDF called ic3374a. The title is unchanged.