
 ccfind 
  xrotation and yrotation are interpreted as the rotation of the ra / longitude and dec / latitude coordinates with respect to the x and y axes, and default 0.0 and 0.0 degrees respectively. 
  CCFIND computes the pixel coordinates of each object by, 1) transforming the input celestial coordinates to image celestial coordinate system, 2) using the image celestial coordinate system to compute the initial pixel coordinates, and 3) computing the final pixel coordinates using a centroiding algorithm. 
  In both the above examples, x and y are the pixel coordinates, xi and eta are the usual projected (standard) coordinates, lng and lat are the celestial coordinates, and PROJ stands for the projection function, usually the tangent plane projection function. 
 stsdas.stsci.edu /cgibin/gethelp.cgi?ccfind (2531 words) 
