Microwave scattering from the ocean surface computed using an extended bistatic scattering model

The authors describe an extension to the Kirchhoff approach, commonly used to describe near-nadir backscattering, to include the proper polarization sensitivity for general bistatic scattering from gently-sloping perfectly-conducting surfaces. This extension is based on a small-slope expansion of the surface-current integral equation. A compact vector notation that significantly simplifies the general description of the polarization of the scattered field is introduced. They show how this extended Kirchhoff scattering model can provide a convenient tool for the analysis of general bistatic scattering problems such as one might encounter in the study of passive microwave emission or GPS-based scatterometry.