修正双尺度模型在非高斯海面散射中的应用

基于海浪在水平及垂直方向上的倾斜效应,应用修正的双尺度模型求解非高斯海面的电磁散射,在经典的一阶微扰散射系数上添加了一个附加散射系数项,它与非高斯海面的双谱函数成正比,且该项反映了海面后向散射系数在逆风和顺风向上观测结果的不对称性.在修正模型中还考虑了遮蔽函数、曲率效应等因素对散射结果的影响.最后应用修正的双尺度模型数值计算并讨论了非高斯海面后向电磁散射特性,修正模型下的计算结果与实验数据有较好的吻合.

Application of modified two-scale model for scattering from non-Gaussian sea surface

Based on the horizontal and vertical skewness of sea waves, a modified two-scale model has been developed for the non-Gaussian sea surface, a complementary term is added to the first-order scattering coefficient of classical SPM (small perturbation method), the additional part is proportional to the surface bispectrum and it is the critical part for explaining the difference between upwind and downwind observations. Meanwhile, in the new modified model, the effects of the shadow function of anisotropic surface, the curvature of the surface on the scattering are also taken into account. Finally, applying the modified two-scale model, numerical illustrations are carried out for the characteristics of the backscattering coefficients from non-Gaussian oceanic surface, good agreements are obtained between the numerical results by the modified model and the measured data.