Modeling of Scattering by Dense Random Media Consisting of Particle Clusters with DMRT Bicontinuous

In this paper, we developed the dense media radiative transfer model (DMRT) for random media with densely packed particle clusters. The dense media are computer-generated by applying the bicontinuous random media characterization. The microstructure of the media is controlled by two parameters: mean grain size 〈𝜻〉 and aggregation parameter 𝒃. Phase matrices and extinction coefficients are computed with full wave simulations. These are then substituted into radiative transfer (RT) equations to obtain backscattering coefficients of the dense media layer with particle clusters. The backscattering has a weaker frequency dependence (e.g. ~2.6 power for 𝒃=𝟎.𝟒) than the Rayleigh scattering of 4th power. Backscattering results exhibit strong co-, cross-polarization (pol), and ratio of cross- to co-polarization. For applications to remote sensing of terrestrial snow at C band, results of DMRT simulations show that cross-polarization of snow volume scattering can be larger than that of soil surface scattering. Recently, this property of strong cross polarization has become a useful satellite remote sensing technique for global retrieval of snow depth. Comparisons of DMRT results are made with ESA Satellite Sentinel 1 C band data and ground-based radar observations. The calculated backscatter is in good agreement with radar measurements for both the co- and cross-polarization.