有耗半空间环境中导体目标电磁散射的快速分析

Fast Analysis of the Arbitrary PEC Target Scattering Problem in a Half Space

应用快速多极子方法求解有耗半空间环境中任意三维金属体的雷达散射特性。对于基函数与测试函数的近场组作用,我们用离散复镜像法严格处理半空间并矢格林函数。在处理远场区时,我们利用实镜像源和反射系数近似计算交界面处远场的作用。通过位于有耗半空间三面角反射器、立方体证明了方法的正确性和有效性。另外,将多分辨预处理器和快速多极子方法结合使得矩阵求解器的迭代次数和计算时间减少数倍。

Fast muhipole method is used for lossy half-space environment arbitrary three-dimensional PEC radar scattering properties. For basis functions and test functions within the near-field. The nearby terms in the FMM framework are evaluated by using the rigorous half-space dyadic Green＇s function, computed via the method of complex images. Non-near （far） FMM interactions are modeled as in the free-space FMM, with the dyadic Green＇s function approximated via real ima- ges and equivalent reflection coefficients, these approximations have proven to be highly accurate, for a large trihedral fidu- cial target and rectangular box, above a lossy half space. Further we use a muhiresolution （MR） preconditioner to precondition the modified FMM, the result shows the MR preconditioner can speed up the convergence rate of the FMM quite well. And this method is extended to the fast multipole method, makes more practical significance.