A site-specific model of radar terrain backscatter and shadowing

A site-specific approach is presented to characterize terrain and target visibility and terrain clutter as seen by a shipboard radar in a coastal environment. The method takes into account the location of the ship, the particular terrain topography, the radar parameters, and the propagation effect. The method incorporates atmospheric refractive index conditions surrounding the radar, an optical ray-trace model, an electromagnetic parabolic equation model, a database of terrain elevations, and a clutter model. The model can simulate illuminated and shadowed regions of both surface clutter and elevated targets. Simulated clutter results are shown to compare favorably with clutter data measured at S-band, X-band, and Ku-band. This correspondence is evident in gee-graphic patterns and statistical distributions of clutter on directly illuminated terrain surfaces.