Atmospheric transmission models for FIFI-LS: altitude 35kft, 39deg O3

They are to be used as the default models for FIFI-LS data reduction with SOFIA Redux The models are generated from a modified atran_sdc based on Steve Lord's ATRAN. The most significant modification is a correction of 17O16O isotopologue abundance coefficients.

The models are stored in FITS binary table format with the columns "wavelength" and "transmission". All models of the same altitude (and same wavelength range) have the same number of wavelength elements. File naming convention: atran_sdc_xxK_yydeg_zzpwv_39deg_2nlayer_40-300mum_bt.fits where xx is the flight altitude in kft, yy is the zenith angle in degree, and zz the precipitable water vapor value in micron.