How to Apply the Distortion Map File †The distotion map can be simply applied by IRAF ccsetwcs command; ccsetwcs (image file) (s11a-band.db) (s11a-band.coo) . How the Files are Made †The distortion map is measured using the data of galactic plane, where the number density of stars are high. ccmap s11a-band.coo s11a-band.db lngunit="degree" latunits="degrees" projection="tnx" xxorder=6 xyorder=6 yxorder=6 yyorder=6 maxiter=3 reject=4 . |