Program Purpose

The ADDMAP program adds or subtracts 2 counts maps as well as the corresponding exposure maps and stores the resulting counts, exposure and intensity maps into FITS format files. Optionally, only the counts maps may be generated if requested by the user. The program has the ability to add maps of different sky regions, bin sizes, grid type (rectangular or Aitoff) and coordinate system (celestial, galactic, earth centered, instrument centered and others).

The program may be used to combine observations of the same region for different viewing periods, or to produce maps of expanded regions such as galactic disk or all sky maps. The option to subtract is then useful when combining several regions by allowing to back up to a previous state and make adjustments.