Investigation on Microwave Polarimetric Scattering from Two-Dimensional Wind Fetch- and Water Depth-Limited Nearshore Sea Surfaces

The microwave polarimetric scattering from two-dimensional (2-D) wind fetchand water depth-limited nearshore sea surface is investigated by using the second-order small-slope approximation (SSA-II). The sea waves are simulated by taking into account the influences of fetch and depth. Based on this, the joint influence of fetch and depth on the normalized radar cross section (NRCS) of sea surfaces for both co-polarizations and cross-polarization in different wind directions is mainly studied. Monostatic and bistatic numerical results both indicate that in the marine environment of small depth and large fetch, the nonlinear interactions among waves become more intense, which has a greater impact on NRCSs for co-polarizations than their cross-polarized counterparts. Comparison of the results for different wind directions also reflects that the backscattered echoes along wind direction have much greater strength, regardless of the magnitude of wind fetch and water depth.