求解目标地波散射特性的方法研究

An Approach for Solving Ground Wave Scattering from Objects

本文把求解半空间散射问题的FDTD技术与地波传播理论相结合，研究任意复杂目标的地波散射特性。入射地波设置在FDTD计算区域中的总场边界上并在散射场输出边界面上提取散射近场数据，然后利用等效及镜像原理，计算无地波衰减时的远区散射场，通过引入地波衰减因子，把该远区散射场转换为远区地波散射场。文中给出了方法验证例子以及一个较复杂目标的单站RCS计算结果。

In this paper, the ground wave scattering from a complex target is investigated by combining the FDTD technique of solving the semi-space scattering problem with the theory of ground wave propagation. The scattered near field is computed first by the FDTD method. The scattered far field without considering the loss of ground wave propagation is obtained through the near to far-zone transformation. This 'lossless' scattered far-field multiplied by an attenuation factor caused by ground wave propagation is then used to represent the ground wave scattering. This approach is applied to evaluate the RCS of a ship on the sea.