MODTRAN (R) 7*: a polarimetric extension of the MODTRAN (R) 6 radiometric atmospheric radiative transfer model

MODTRAN7, a polarimetric extension of the MODTRAN6 atmospheric radiative transfer model, is being developed. The vectorized MODTRAN7 will provide band model (BM), correlated-k (Ck), and line- by-line options for computing Stokes vectors. The radiative transfer problem is being solved for Isotropic and Symmetric Media (ISM) using the basic phenomenology described in the classic text by Mishchenko, Travis and Lacis, "Multiple Scattering of Light by Particles" 1. VDISORT, a vectorized version of the DISORT scalar model currently in MODTRAN6, will compute the Stokes vectors for 1-D atmospheres. The MODTRAN method for extracting spherical refractive path contributions from the plane parallel scattering models will be adapted for the polarimetric model. The upgrade is to include new polarimetric optical properties for both the existing aerosol and cloud models within MODTRAN and for recently developed cirrus cloud and dust particulate data. A new algorithm has been developed that enables Generalized Spherical Function (GSF) expansion coefficients to be accurately computed to very high order. MODTRAN has already been restructured to generate Stokes vector data for single scatter solar/lunar applications and validated against the NASA Goddard Space Flight Center model, 6SV.