海面上电大尺寸目标电磁散射特性研究

Research on Electromagnetic Scattering from Large Object on Ocean Surface

基于几何光学法(GO)、物理光学法(PO)、射线弹跳法(SBR)和等效电流法(MEC),提出了一种快速计算金属海面上电大尺寸目标电磁散射的解析算法。该算法考虑了阴影效应,运用GO/PO+SBR计算了目标与海面的镜面反射以及它们之间的多次相互作用,并运用MEC计算了目标的棱边绕射以改进计算结果。应用该算法计算了平板上方规则金属目标的双站雷达散射截面(RCS),并与传统矩量法(MoM)进行比较,验证了算法的有效性。最后,计算了PM(Pierson-Moskowitz)海浪谱的随机海洋粗糙面上舰船模型目标的散射特性,并对计算结果进行了分析,讨论了海洋面以及入射波参数对散射结果的影响。

A new method is proposed to rapid compute the electromagnetic scattering from the large object on ocean surface. This method combines the Geometric Optic （GO）, the Physic Optic （PO）, the Shooting and Bouncing Ray （SBR） and the Method of Equivalent Currents （MEC）. The interaction between object and ocean surface is computed by using GO/PO＋SBR, and the result is improved by MEC which takes into account the edges diffraction. The shadowing effect is also included. The radar cross section （RCS） of regular metal object located on ocean surface is computed by using this method. The validity of this method is proved by comparing with the traditional method of moment （MoM）. Finally, a aircraft carrier object located on random ocean rough surface with PM （Pierson-Moskowitz） spectrum is computed, The result is analyzed, and the influence on scattering characteristic caused by parameters of ocean surface and incidence wave is discussed.