Browsing Images in World Coordinate Space with SAOimage

Since the advent of astronomical image serving over the World Wide Web, SAOimage, developed in the late 1980's at the Smithsonian Astrophysical Observatory, has been used as an image viewer. More and more images, especially those from large surveys, contain information in their headers linking spatial coordinates (world coordinate systems) to image pixel coordinates. SAOimage has been augmented to track the position of the cursor in world coordinates as well as image pixel coordinates in FITS and IRAF images containing appropriate information in their headers. On-line documentation, including program access and installation directions and pointers to images servers, is available on the World Wide Web at URL \it http://tdc-www.harvard.edu/software/saoimage.html.