Analysis and Simulation of Low Grazing Angle X-Band Coherent Radar Sea Clutter Using Memoryless Nonlinear Transformations

Two examples of low grazing angle radar sea clutter, both well-described by the compound
$K$
-distribution model, are studied. Pulse Doppler processing is applied to obtain 2-D range–time textures for the intensity, centroid, and width of the Doppler spectrum. The first example exhibits a monochromatic swell pattern, allowing phase averaging to be applied to the textures. The second example has a more typical ocean wave spectrum. The intensity textures are gamma-distributed, consistent with the compound
$K$
-distribution model, but the Doppler spectrum centroid and width textures are also found to be gamma-distributed. Based on this analysis, a new method for simulation of coherent radar sea clutter is proposed, where separate memoryless nonlinear transformations are applied to a simulated water surface to generate the spatially and temporally varying intensity, centroid, and width of the Doppler spectrum. The method builds on the evolving Doppler spectrum model for radar sea clutter simulation and established methods for simulation of water surfaces.