Image World Coordinate Setting Program

imwucac2 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.

imwucac2 uses the USNO UCAC2 Catalog, an updated version of the USNO UCAC Catalog containing 48,366,996 stars with positions and proper motions. It has been superceded by the USNO UCAC3 Catalog, with 100,766,420 stars.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 17 December 2009 by Doug Mink Telescope Data Center [WCSTools Programs]