Image World Coordinate Setting Program

imwtmc is an alias for imwcs, a program which sets the world coordinate system (WCS) of a FITS or IRAF image. The WCS is the relationship between sky coordinates and image pixels and can be described in a standard way in the header of an image. The program was originally written at the University of Iowa, but has been adapted and amplified by Doug Mink at the Smithsonian Astrophysical Observatory.

imwtmc uses the 2MASS Point Source Catalog, but it doesn't yet cover the entire sky. The GSC II Catalog (imwgsc2) is a visible catalog which covers the entire sky with positions which are about as good. The USNO-A2.0 catalog (imwua2) has more stars, but is based on plates taken in the 1950's, so its accuracy has been decreased by proper motion of its stars.

A set of image stars may be hand-matched to sky positions and used to get a WCS or set initial values for a reference catalog-based WCS (See example).

Command Line Arguments


Using SExtractor to find stars in an image

Find image WCS using HST Guide Stars as references

Find image WCS using pre-matched stars and USNO-A2.0 Stars

Last updated 19 October 2001 by Doug Mink

Telescope Data Center [WCSTools Programs]