复合目标电磁散射的高效混合计算方法

传统混合法在计算目标与粗糙面的耦合场时，需要耗费大量内存与时间。以计算复合目标后向电磁散射为目的，提出一种更为高效的混合计算方法。该混合法在单独处理粗糙面与目标方面与传统混合法一致，即使用基尔霍夫近似法（Kirchhoff approach,KA）处理粗糙面区域；使用矩量法（method of moment, MoM）并结合多层快速多极子（multilevel fast multipole algorithm, MLFMA）技术处理目标区域。与传统混合法所不同的是：根据大尺度粗糙面镜向散射最强的特点，只在粗糙面上截取一块很小的区域进行耦合场计算，从而极大减少内存与时间。大量数值实验表明,该方法在保证较高精度的同时，效率要远高于传统混合法。

Highly efficient hybrid method for monostatic scattering by objects above rough surface

It is known that the expensive step in the conventional hybrid method of the Kirchhoff approach (KA) and the method of moment (MoM) is to calculate the interaction between objects and the rough surface. A highly efficient hybrid method is proposed for calculating the monostatic scattering by objects above a rough surface. Similar with the conventional hybrid KA MoM, the KA is used to calculate the scattering by the rough surface, and the MoM with multilevel fast multipole algorithm (MLFMA) is applied to calculate the scattering by the objects. The main difference between the proposed method and the conventional KA MoM algorithm is that the size of the rough surface is truncated for calculating the interactions between the objects and the rough surface, which depending on the specular reflection of the large scale rough surface. The accuracy and efficiency of the proposed method are studied by numerical experiments. The results show that by executing the truncation, the memory and the computation time are significantly reduced.