Surface Roughness and Microwave Surface Scattering of High-Resolution Imaging Radar

This study aims to understand the effects of spatial resolution on the surface backscattering characteristics of polarimetric radar. Surface scattering models based on approximate methods are formulated by the roughness second-order statistics to obtain a closed-form expression for the radar scattering response. Most studies have been carried out based on the roughness parameters of the infinite surface. In this letter, we propose the roughness autocorrelation function of truncated surfaces for a more realistic description of the roughness parameters of high-resolution radar. The use of roughness parameters for a truncated surface in the scattering model is pertinent to explain the dependence of the backscattering coefficient on the spatial resolution. Simulation results indicate that the traditional computation of the surface backscattering based on the autocovariance function of an infinite surface leads to an underestimation of the backscattering signature of the high-resolution radar.