RADIATIVE-TRANSFER IN A SCATTERING MEDIUM WITH ANGLE-DEPENDENT REFLECTIVE BOUNDARIES

Radiative transfer in an anisotropically scattering slab with directio n-dependent reflectivities at the interfaces is solved using the Pomra ning-Eddington variational method. The interfaces are assumed to refle ct specularly as a function of angle of incidence according to Fresnel 's equation. The quantities of interest, such as the hemispherical ref lectivity and transmissivity of the medium, are calculated for differe nt optical thicknesses, single-scattering albedos and refractive indic es of the medium. The results are compared with the exact numerical re sults and with those obtained using the average value of the reflectiv ities instead of the angle-dependent Fresnel reflectivity. Calculation s are also performed for a semi-infinite medium and compared with resu lts calculated using the average reflectivities.