Terrain Clutter Simulation using Physics-Based Scattering Model and Digital Terrain Profile Data

Site-specific terrain clutter models based on digital terrain elevation data (DTED) have been in existence for many years due to their importance in remote-sensing and military radar, just to name a few. We propose a simple site-specific terrain clutter modeling approach that takes advantage of DTED information in a more consistent manner by combining it with physics-based rough-surface scattering models. Terrain profile information is used to generate a triangulated facet model of the terrain surface under investigation. A light-of-sight analysis is then performed to differentiate the illuminated facets from the shadowed ones for given radar geometry. The orientation of each illuminated facet is computed with respect to the radar's line of sight. The complex reflectivity of each illuminated facet is subsequently computed using a physics-based, rough-surface model appropriate for the radar frequency and the relative roughness of the terrain. The total clutter power is finally computed by summing up the contribution from each facet. In this work, the small perturbation method (SPM) is used to compute the reflectivity of each facet. Using our model, we investigate the respective impacts of polarization, radar geometry, and small-scale surface roughness on the total clutter power.