Comparison of Solutions of Radiation Transfer Equation Obtained by Methods of Spherical Harmonics and Ray Tracing for Complex Curvilinear Geometry

Results of numerical solving of the radiation transfer equation (in P₁-approximation of spherical harmonics method) for the non-scattering medium that corresponds to the Martian atmosphere are presented. Thermal characteristics are calculated for two cases of the volume coefficient of radiation absorption: when it is constant in space and with account for multicomponent composition of the medium. In order to take into consideration spectral features of the absorbing-radiating medium, the calculation is performed in the multigroup statement for the wide spectral range using two types of structured curvilinear grids with different number of nodes. Density values of radiation fluxes to the spherical body surface obtained by solving the radiation transfer equation in diffusion approximation are compared to results of its solving by the ray tracing method.