Rigorous Simulations of Microwave Scattering From Finite Conductivity Two-Dimensional Sea Surfaces at Low Grazing Angles

We present a boundary integral method for the solution of the rigorous problem of microwave scattering from finite conductivity sea surfaces under grazing illumination. Following the locally perturbated plane approach, the roughness is flattened at the edges of a finite patch, allowing us to use a plane wave as incident field. Both theoretical formulation and numerical implementation are addressed. We present simulations of full-polarization radar cross-sectional diagrams for 2-D ocean-like surfaces in both bistatic and monostatic configurations. The conductivity of the sea water is taken into account with a curved surface-impedance approximation, and results are compared with a perfectly conducting surface model. Simulations are finally confronted to approximate theories and empirical sea backscatter models for low grazing angles at L-band, vertical polarization, and a wind speed of 3 m/s.