SAR resolution degradation estimation operating in sparse random media at millimeter-wave frequencies

Resolution degradation in both the cross-range direction and range direction of SAR systems operating in sparse random media at millimeter-wave frequency is studied using a novel coherent propagation model that accounts for multiple scattering in the medium. For the purpose of demonstration, a 2D random medium composed of electrically large scatterers with high dielectric contrast and low surface fraction value is considered. The study is motivated by assessing the performance of future sub-millimeter-wave (sub-MMW) SAR systems with unprecedented imaging resolution working in a rainy environment. Monte Carlo techniques combined with a novel simulation algorithm called Statistical S-matrix Approach for Wave Propagation in Spectral Domain (SSWaP-SD) are used to efficiently characterize the resolution degradation of the SAR system. It is shown that the cross-range resolution degradation is severe for long distance wave propagation inside the random medium, while the range resolution degradation is much less.