Simulation of microwave emission and backscattering of layered snowpacks by a radiative transfer model, and validation by surface-based experiments

A thermal microwave emission model of layered snowpacks (MEMLS) has been previously developed for the frequency range, 5 to 100 GHz. It is based on six-flux radiative transfer to describe multiple volume scattering, absorption, and refractive effects. MEMLS is a physical model with a semi-empirical part in the description of the scattering coefficient, and later this element was completed by a fully physical scattering theory. Model validation included surface-based radiometer experiments and detailed in-situ data. In a further step to be presented in the present article the authors tested MEMLS by using Chandrasekhar´s H-functions. They show how they can be applied to a refractive medium such as snow. As an effect of refraction a Lambert-like behavior is obtained. Since the formalism is bistatic, it also delivers the backscattering coefficient, yielding the link to radar data. Data from active and passive microwave experiments will be used to test the models