POLARIZATION DEPENDENCY OF ENHANCED MULTIPATH RADAR BACKSCATTERING FROM AN OCEAN-LIKE SURFACE

Previous analyses of electromagnetic scattering from a two-scale ocean surface assumed the tilts on a large-scale surface to be small. This means that multiple scattering between large-scale roughnesses is insi gnificant. If the tilts are not small, multipath-enhanced backscatteri ng may occur due to quasi-specular reflections between the opposite sl opes of a large-scale surface component. We have considered the simple st situation; this involves one reflection from the large-scale compon ent and one single-scattering from the small-scale component. The cohe rent addition of this process to the reciprocally reverse one creates multipath-enhanced backscattering. The relative gain in the HH backsca ttering cross section up to the level of the VV signal was obtained fo r surface-wave slopes of about 30 degrees and for large incidence angl es. This gain occurs because the VV signal experiences an extinction d uring reflection at incident angles close to the pseudo-Brewster angle . The presented model provides insight into one scattering mechanism t hat is possibly responsible for the departure of radar sea experimenta l data from predictions by the conventional two-scale model.