Atmospheric/topographic correction is the elimination of atmospheric and illumination effects to retrieve physical parameters of the earth's surface, i.e. surface spectral reflectance, emissivity and temperature. The ATCOR® products solve this task using look up tables calculated with the Modtran® 5 radiative transfer code. The ATCOR® models has been split into separate codes optimized for satellite sensors and airborne sensors:
- The satellite ATCOR® (ATCOR-2/3) supports only small to moderate FOV sensors and consists of separate codes for flat and rugged terrain. It includes a large database of atmospheric correction functions (look-up-tables computed with the Modtran® 5 radiative transfer code) covering a wide range of weather conditions, sun angles, and ground elevations.
- The airborne ATCOR® (ATCOR-4) corrects small and wide FOV airborne optical and thermal scanner data. It interpolates the solution from an extensive Modtran®-derived atmospheric database for typical flight altitudes and solar geometries.