矩量法-物理光学混合算法计算多尺度复合目标电磁散射场

基于电流的矩量法（method of moments，MoM）和物理光学法（physical optics，PO）的混合算法是目前求解电中尺度和多尺度目标电磁散射和辐射的主要方法，在计算MoM区和PO区的耦合作用时需要对PO区域进行亮区判断.传统纯CPU亮区判断方法时间复杂度为O（N2），时间消耗随着面片数量N增加而急剧增大.文中通过GPU渲染功能及对深度缓冲区（zbuffer）的利用，对PO亮区判断过程进行加速，亮区消耗时间与面片数量无直接联系，在面片数量达到105数量级以上加速优势明显.将加速的MoM-PO混合方法应用于复杂目标与粗糙面的组合情况，对比多层快速多级子（multi level fastmultipole method，MLFMA）方法，相比于纯PO方法，获得较高的精度.相比于单一算法，混合算法有明显优势.

The MoM-PO hybrid method for calculating the scattered field of multi-scale composite targets

Method of moments (MoM) and physical optics (PO) hybrid algorithm is the main method for calculating scattered field of electrically mid-scale and multi-scale target. When calculating the coupling effect between MoM region and PO region, we have to judge whether the PO elements is illuminated. Time complexity of shadowing algorithm based merely on CPU is O (N2) where N represents to the patch number of the target, which increases sharply with the increase of patch number. In this paper, we use GPU rendering and zbuffer to accelerate the process of lit judge. The time consuming of shadowing process has no relation with increasing patch number and has a better performance especially when the patch number reaches 105 magnitude. We apply MoM-PO method to the scattered field calculation from the complex target combined with rough surface. Compared with the multilevel fast multipole algorithm (MLFMA) and PO method, this hybrid method achieves high precision. The hybrid algorithm has obvious advantage over single method algorithm.