高斯粗糙表面低掠入射散射特性研究

Study of Low-Grazing Angle Scattering Effect from Gaussian Rough Surface

该文针对传统解析法不能有效求解低掠入射下粗糙表面散射特性的问题,提出了一种高阶解析法,该算法基于表面散射场的高阶分量和表面轮廓函数的高阶Taylor级数展开。利用该算法,定量比较了同极化的高、低阶散射系数,讨论了低掠入射下不同粗糙度的散射特性,分析了低掠入射下高阶微扰法和高阶基尔霍夫法求解高斯粗糙面的修正效应,得出了高阶解析法可以很好求解低掠入射问题的结论。最后,还研究了同极化散射指数与掠入射角幂函数的拟合问题,修正了极化散射指数的经典表达式。

To investigate the problem of classical analytical method, which can not be used at Low-Grazing Angle （LGA） for rough surface scattering, a new high-order analytical method based on the high-order series expansion of the two-dimensional electric field and the profile function of rough surface is adopted. By this arithmetic, the co-polarized backscattering coefficient at LGA is compared with high-order Small Perturbation Method （SPM） and classical SPM, the grazing effect at different roughness is discussed, the modified effect for Gaussian rough surface at LGA is analyzed by high-order SPM and high-order Kirchhoff Approximation （KA）. The result shows that the high-order analytical method is valid for LGA problem. At last, the vertical-to-horizontal Polarization Ratio （PR） with different power of secant function of grazing incident angle and scattering angle is considered particularly, and the classical expression of PR is rectified.