EM scattering from sea surface in the presence of wind wave patterns

In order to relate the scattered EM signal with some basic statistical parameters of the random wave field the key "random phase" hypothesis is commonly used. The wave field is presumed to be entirely specified by its spatial energy spectrum, while the phases of the Fourier harmonics constituting the relevant statistical ensemble are assumed to be randomly distributed. The relevant ensemble is specified by time or spatial averaging of the measurement under consideration. This hypothesis, although providing a reasonably good first approximation for many, but not all, cases and having obvious advantage of utmost simplicity, is nevertheless in contradiction with more accurate observations in laboratory and sea. Often the presence of wave patterns is easily discernible on the sea surface, moreover, there is always a strong correlation of amplitudes and phases at least among some components of wind wave field. This work is based upon the idea that, since the EM scattering employed in remote sensing has a very selective resonant nature, such correlation of even a small fraction of wave field can essentially change the reflected EM signal. The authors show why and when this happens. More specifically, they relate the problem of EM scattering by sea surface with water wave nonlinear dynamics, which implies certain preferred phase relationships among the interacting harmonics. They also suggest quantitative methods of how to estimate a priori this effect by analyzing certain statistical moments of sea surface