植物伪装遮障下车辆目标电磁散射精确仿真研究

Study of Accurate Simulation for Electromagnetic Scattering from Vehicle Under Vegetation Screen

为了精确研究植物遮障下电大尺寸金属目标电磁散射特性,提出了一种高效混合计算模型。通过构造真实树结构对植物遮障的散射建立多层频域计算模型;基于时域有限差分方法,对目标区域的散射建立时域计算模型。运用互易性原理连接植物遮障计算模型与目标区域计算模型,避免了植物遮障与电大尺寸金属目标间复杂的电磁场相互作用,建立了对植物遮障下电大尺寸金属目标的高效、精确电磁散射特性仿真模型。通过以角反射器和典型金属车辆为目标的电磁散射计算实验,证明该方法正确、有效。

An accurate simulation model is proposed to investigate the electromagnetic scattering behavior of electrically large targets under a vegetation screen accurately. The proposed model is composed of two electromagnetic-scattering sub-models. One makes use of realistic tree structures for founding multilayer vegetation scattering model in frequency domain. The other founds target scattering model in time domain based on finite difference time domain method. The electromagnetic interaction between electrically large target and screen is avoided very efficiently by using a reciprocity theorem to connect the two sub-models. The proposed method is proved to be exact and valid by electromagnetic computation tests for a dihedral corner reflector and a electrically large vehicle.