Theoretical studies of ocean polarimetric brightness signatures

Recent measurements of ocean polarimetric thermal emission have shown interesting variations in brightness temperature azimuthal harmonics with polar observation angle. To investigate these variations, polarimetric thermal emission from two dimensional sinusoidal surfaces is considered through both analytical (small perturbation method and physical optics) and numerical (extended boundary condition) models. Results demonstrate the applicability of both approximate techniques for the calculation of emission from surfaces with small slopes and large scale features, even when perturbation theory fails completely for the prediction of reflected mode amplitudes. Although a two dimensional sinusoidal surface is a greatly simplified model for the ocean, the simplicity of this geometry makes it possible to obtain analytical perturbation theory results for emission azimuthal harmonics which allow physical insight into the emission process.