A refined composite surface model for numerical investigation of backscattering from wind-driven sea surface

Microwave backscattering from two-dimensional wind-driven sea is investigated by using a refined composite surface model. In this composite model, a new choice of the cutoff wave number with wind-speed dependence and incident-frequency dependence is applied to separate the sea spectrum into large and small components in different sea states with increased accuracy. Meanwhile, a newly modified probability density function is exploited to illuminate the skewness effect of sea surface between upwind and downwind direction. Applying the refined composite model, the backscattering coefficient from wind-driven sea is calculated and discussed, good agreements are obtained between the results by the refined model and the experimental data.