The joint influences of wind fetch and water depth on Doppler spectrum of dynamic nonlinear ocean surfaces

The wind fetch and water depth will greatly impact the ocean waves from the perspective of their shape and statistical characteristics. In this paper, special focus is given to the joint influence of wind fetch and water depth upon Doppler spectrum of dynamic nonlinear ocean surfaces. The study is based on the simulation of two-dimensional fetch- and depth-changed sea surfaces via nonlinear revised choppy wave model (RCWM). Then the Doppler spectral characteristics of echoes from simulated surfaces are mainly analyzed in detail by applying second-order small slope approximation (SSA-2).