有耗媒质中目标体散射特性的TSNU-PSTD模拟

结合PML边界条件的傅立叶时域伪谱(PSTD)算法已被广泛用于模拟电磁波传播和目标散射,但传统的PSTD方法在每个坐标方向上需要均匀分布的空间坐标网格点,因而不能够很好地模拟曲面目标和与网格空间尺寸不一致的目标,基于变空间非均匀网格的PSTD(TSNU-PSTD)方法可以很好地克服这些不足。将CFS-PML边界条件应用在PSTD算法中,并将其与TSNU-PSTD方法相结合模拟了大范围有耗媒质中介质体目标的电磁散射,部分计算结果与FDTD计算结果进行了比较。仿真结果表明,TSNU-PSTD算法只需平均每波长分成3个网格就可以得到令人满意的计算结果,可高效地分析大范围有耗媒质中曲面形状目标体的散射特性。

Simulations of Scattering by the Objects Buried in Lossy Media Using TSNU-PSTD Algorithm

A technique based on the combination of Fourier pseudospectral time-domain method(PSTD) and PML absorbing boundary conditions is widely used to simulate the scattering and propagation problems.However,one of the known disadvantages of this method is that it requires a uniformly distributed spatial grid-set along each orthogonal direction.But its accuracy is lower when applied to the objects involving the curved boundary or thein dimensions are not commensurate with the cell size.The PSTD method involving space transformations(TSNU-PSTD) alleviates this limitation.The CFS-PML is implemented in the PSTD and the TSNU-PSTD algorithm combined with the CFS-PML has been applied to model ground-penetrating radar(GPR) application involving objects in a large-scale lossy half space,and the results are compared with the FDTD.Numerical simulations show that it can achieve a satisfactory result with a grid density of only 3.0 nodes per minimum wavelength,and can simulate the scattering of curved objects in large-scale lossy media efficaciously.