-Same as LOWTRAN except -Includes the two-parameter MODTRAN band model -Calculates atmospheric transmittance and radiance from 0 to 50,000 cm-1 at 2 cm-1 resolution -More realistic temperature-dependent model -Includes high- altitude transmittance/radiance calculations up to 60 km -Include water vapor, carbon dioxide, ozone,nitrous oxide, carbon monoxide, methane, oxygen, nitric oxide, sulfur dioxide, ammonia, and nitric acid