WCSTools Subroutines

Processing Subroutines

FindStars( ) gets the location and brightest pixel of stars in the given image. Included are subroutines to find and reject bright pixels and compute a star centroid. Based on code by Elwood Downey, UIowa

rotFITS( ) rotates an image by 90, 180, or 270 degrees, with an optional left-right reflection before the rotation.

SetWCSFITS( ) uses findStars to find the stars in an image, gscread to find the Guide Stars in the nominal image region, any of four matching methods to register image stars with catalog stars, and a fitting subroutine to fit a plate-tangent WCS to an image. Based on code by Elwood Downey, UIowa)

StarMatch( ) takes a list of reference star positions and a list of object coordinates from an image and finds the image offset which matches the most reference objects to the most image objects.

FluxSortStars( ) sorts a list of stars by flux. MagSortStars( ) sorts a list of stars by magnitude, where the magnitude occupies the same variable as the flux would have. RASortStars( ) sorts a list of stars by right ascension.

Defaults for parameters used by processing subroutines. Many of these can also be changed on the command lines of the programs which use the affected subroutines.

Last updated 31 July 2018 by Jessica Mink, SAO Telescope Data Center