In the study of microwave remote sensing and wave propagation in a medium, it is interesting and important to model and calculate the interaction of the electromagnetic wave with the medium. In this book, the backscattering model for an electrically dense medium is presented. This model considers the multiple surface scattering effect together with the single surface scattering effect and includes up to second order surface-volume scattering on the scattering formulation. Theoretical analysis on sea ice and snow layer is done to study the effects of including the surface multiple scattering and surface-volume scattering up to second order in the model. Comparisons made with the field measurement results are also shown in this book. Ground truth measurement data from the field trip to Antarctica done by team members from Multimedia University are used for comparison with the satellite measured data.