Use a FITS image for which a rough WCS has been determined. Using the cdfp catalog of this image, cross-match to a USNO catalog of the corresponding field. Clean resulting sample of [RS,DEC,X,Y] and redeirve a more accurate set of WCS coefficients.

This is a rather high-level script that call a number of other scripts and routines. I decided to keep a set of notes during the initial assembly of wcs_cdfp_refit.