FASCODE for the Environment

Abstract : FASCODE for the Environment (FASE) is the latest in a long line of atmospheric transmittance and radiance models developed by the Battlespace Environment Division of the Air Force Research Laboratory (AFRL), formerly known as the Optical Physics Division of the Geophysics Directorate, USAF Phillips Laboratory, and before that, the Air Force Geophysics Laboratory (AFGL). FASE is a direct descendent of the line-by-line atmospheric transmittance/radiance model FASCOD3. It also incorporates recent developments from the similar model LBLRTM. This report presents the additions and improvements in FASE over previous models, including: (1) improvements and corrections to the geometry routines, (2) corrections to the NLTE routines, (3) corrections to the blackbody function when aerosols are included, (4) corrections and improvements to the Hartley-Huggins and the Hertzberg continua, (5) corrections to the calculations of absorption cross-sections and to the laser calculation, (6) addition of the Schumann-Runge Band and continuum, (7) inclusion of a solar spectrum module, (8) inclusion of a spectral limit check when line coupling is included, and (9) acceptance of the HITRAN96 line parameters.