Modeling of emission from snow-covered ground for passive microwave remote sensing

This paper investigated the emission behavior at 18.7 GHz, 36.5 GHz and 89 GHz over the snow-cover surface and after snow completely removed surface at the Local Scale Observation Site (LSOS) in Fraser, Colorado, USA with 55° incidence angle) using one-layer and two-layer emission model, which is based on the radiative transfer by Matrix Doubling approach with the dense media theory and the surface scattering Model. From the comparisons with the GBMR-7 observation on Feb. 21, both the two-layer emission model and one-layer emission model could predict the observed brightness temperature over snow-covered surface well, but the polarization difference predicted by two-layer emission model was relatively smaller than one-layer model did. In addition, we attempted to interpret the emission magnitude and polarization separation of snow-removed surface by incorporating a transition layer below the soil medium. We also demonstrated the effect of snow fraction on the brightness temperature difference at 18.7 GHz and 36.5 GHz over snow-cover surface with the field observation and model simulation.