高斯介质粗糙表面电磁散射的高阶基尔霍夫法

High-order kirchhoff approximation for gaussian dielectric rough surface electromagnetic scattering

针对基尔霍夫近似(KA)求解精度的问题,提出了一种均方高度高阶级数展开的改进算法。该算法基于粗糙表面斜率的零阶展开和二阶展开近似,得到了考虑斜率效应的高阶KA的求解结果。通过阴影函数的修正有效补偿了在大入射角下散射系数计算的偏差。分析了考虑斜率效应及阴影函数时的后向增强现象,通过数值计算比较证明了该算法的有效性。

To investigate the precision of Kirchhoff approximation, a new arithmetic for the high-order series expansion of the root-mean-square height is presented. Using the zero-order and second-order slope expansion approximation, the bistatic scattering and backscattering coefficients are derived. The error is eoriected with the high-order shadowing function, Based on the slope and shadowing effects the enhancement effect is analyzed. The result shows that the new method is valid and precise in a more extensive boundary.