Bistatic Clutter RCS Simulation Using Scale Model Rough Surfaces

摘要

Bistatic scattering cross section measurements of CO2, laser radiation fromroughened metal and dielectric surfaces were made and compared to predictions given by the facet model. The scattered polarization state was analyzed along two directions, perpendicular (HH) and parallel (HV) to the scattering plane. The (sigma ) HH nulls predicted by the facet model have been verified at steep incident angles for both metallic and dielectric surfaces. Agreement is generally better for metals than dielectrics. At shallower angles measurements diverge from theoretical predictions. A number of calculations of polarization dependent scattering cross sections from metal and dielectric cylinders of radius r as a function of r/lambda have been performed. These calculations suggest that even for large radii surfaces, rapid amplitude and phase variations are responsible for the onset of depolarization at shallower incident and scattering angles, leading to the disagreement with the tangent plane model predictions. They also clearly demonstrate why the facet model is a better approximation, in the region of validity, for metals than dielectrics. The experimental measurements are described in detail and data for both roughened metals and dielectrics are presented for several scattering aspect and depression angles. Bistatic scattering, Scattering measurements, Rough surface scattering.