二维海面上方金属目标复合散射快速算法研究

为快速获取二维海面上方金属目标的复合散射,通过改进计算分层粗糙面散射的层内波传播展开法(PILE),结合快速计算二维粗糙面散射的稀疏矩阵平面迭代与规范网格法(SMFIA/CAG),以及计算金属目标散射的基于三角屋顶(RWG)基函数的矩量法(MoM),提出了结合稀疏矩阵平面迭代及规范网格法的扩展层内波传播展开法(E-PILE+SMFIA/CAG)。引入锥形入射波以减小人为截断粗糙面所引起的边缘衍射,采用蒙特卡洛(Monte-Carlo)模拟生成具有Pierson-Moskowitz(PM)海浪谱的随机海洋粗糙面。数值分析了海面上方典型导体目标的复合双站散射系数,验证了算法的有效性与收敛性。最后,应用该算法计算了海面上方导弹目标的电磁散射,讨论了目标高度及海面上风速对复合散射系数的影响。

Fast algorithm of calculating the composite scattering from PEC object above sea surface

In order to quickly calculate the composite electromagnetic scattering of the object above sea surface,the E-PILE+SMFIA/CAG is present in this paper,which combines the sparse-matrix flat-surface iterative approach-canonical grid(SMFSIA/CAG) method for sea surface and the method of moment(MoM)based on Rao-Wilton-Glisson(RWG) function for object.The tapered incident wave is chosen to reduce the truncation error.The Pierson-Moskowitz(PM) random sea surface is generated by using Monte-Carlo method.The composite bistatic scattering coefficients(BSC) of regular objects above sea surface are calculated by using introduced method.The validity of this method is verified by comparing the results with that of exist method.The BSC from a missile target above sea surface is calculated finally,and the dependences of bistatic scattering pattern upon the wind speed and the height of target is discussed.