A Model for the Mean RCS of a Target Above a Randomly Rough Surface

A fully polarimetric bistatic formulation of the average radar cross-section (RCS) of a target above a rough surface is presented. A four path model approximation of interaction between the surface and the target is used in order to decouple scattering from the target and surface. Surface scattering is described using the small-slope approximation. The ensemble average over surface realizations of the radar cross-section is performed analytically for paths that undergo single scattering from both the target and surface. This approach eliminates the need for Monte Carlo simulations over rough surface realizations and the need to mesh large surfaces in computing the average target plus surface RCS. Predictions from the formulation are shown for plate and cylinder target geometries for a variety of rough surface properties. Predictions are also compared with other results from the literature and found to be in good agreement (within 1.5dB RMS error for the results shown).