Three new coordinate transformation tasks imcctran , skyctran , and wcsctran have been installed in the new IRAF V2.11 imcoords package. The following examples demonstrate the basic functionality of the new tasks. Imcctran converts the image coordinate system from one celestial coordinate system to another. The conversion shifts and rotates the image coordinate system but leaves the pixel coordinates of the reference point and the coordinate projection unchanged.
Precession is treated as a special coordinate conversion.
The following example converts the coordinate system of wpix from equatorial B1950.0 to equatorial J2000.0 and then from equatorial J2000.0 to galactic. The initial image copy avoids overwriting the header of wpix which is used in later examples. The tasks wcsctran and skyctran convert from pixel to world coordinates and vice versa using the image coordinate system. Wcsctran works on images of any dimension with any valid coordinate system. The task skyctran works only on two-dimensional images with valid celestial coordinate systems.