Averaged rough surface backscattering vs. bispectral characteristics of surface shape

For an ensemble of wavy surfaces simulating the sea surface, the relation between the averaged resonant backscattering and bispectral surface shape characteristics is studied by means of computer simulation. It is found that for some bispectral characteristics describing waveform peakedness, skewness, ripple concentration, there is a significant correlation to the averaged amplitude of the backscattered signal, the surface spectrum being the same over the ensemble. As an application, a new sea-way model involving, besides to spectral, these bispectral parameters is proposed. This model can describe the manifestation of nonlinear sea-way effects (such as wind-wave interaction, slicks, etc.) in radar images of the sea surface, whereas traditional random phase model (RPM) uses only spectral parameters and thus cannot describe these effects.