Reformulation of the MODTRAN band model for higher spectral resolution

The MODTRAN 1 cm(-1) band model has been reformulated for application to higher spectral resolution. Molecular line center absorption is still determined from finite spectral bin equivalent widths but is now partitioned between the bin containing the molecular transition and its nearest neighbor bin. Also, the equivalent width calculation has been upgraded to retain to maintain high accuracy at the increased spectral resolution. The MODTRAN Lorentz line tail spectral bin absorption coefficient data has been replaced by a more general and accurate Pade approximant for Voigt line tails, and higher order pressure dependencies are now modeled. Initial comparisons to the FASE model and to measurement data are presented.