Simulation of coherent radar backscatter from dynamic sea surfaces

Direct numerical simulations are used to evaluate the properties of sea clutter at low grazing angles. Electromagnetic calculations are based on iterative solution to the frequency-domain integral equation for the surface current. Performing calculations at multiple frequencies and for sequential surface profiles, range-resolved time-varying radar response from the dynamic surface can be simulated. At present, ocean surface is generated using spectral-based slightly non-linear model that accounts for interactions of smaller ripples with longer waves but does not include any wave breaking. The paper addresses the computational aspects of the simulations and discusses initial results of Monte Carlo study of low grazing surface clutter. While calculations have to be limited to a two-dimensional space, they serve as a useful benchmark for analytical models and have direct application for commonly occurring three-dimensional geometries.