三维随机粗糙面上导体目标散射的解析-数值混合算法

提出三维导体目标与导体粗糙面复合散射的解析-数值混合迭代算法，推导出三维目标与粗糙面的耦合积分方程，以及粗糙面散射的Kirchhoff近似(KA)计算式.粗糙面的KA解析计算大大降低了粗糙面求解的复杂度，与目标矩量法的混合迭代保证了计算结果的精度，使得三维体-面目标复合散射计算变得可行.由于体-面两者的高阶耦合作用明显减小，保证了该混合迭代算法的收敛性.与镜像Green函数方法的比较表明该混合算法的有效性，并讨论了粗糙面长度选择对计算结果的影响.结合Monte-Carlo方法，数值分析了理想导体Gauss 关键词： 复合散射 Kirchhoff近似 共轭梯度法 互耦迭代

A hybrid analytical-numerical algorithm for scattering from a 3-D target above a randomly rough surface

This paper presents a hybrid iterative algorithm of analytic KA-numerical MOM for scattering computation from a 3-dimensional (3-D) perfect conducting target above a randomly rough surface. The coupled integral equations (IEs) are derived for difference scattering computation. The method of moment (MoM) with the conjugate gradient (CG) approach is used to solve the target's IE，and the Kirchhoff approximation (KA) is applied to scattering from the rough surface. The coupling iteration takes account of the interactions between the target and the underlying rough surface. The convergence of this hybrid algorithm of KA-MoM is numerically validated. Since there is only one numerical integral along the rough surface performed for KA computation，memory and CPU time are significantly reduced. Numerical results of bistatic scattering from a PEC ellipsoid or cubic target above a Gaussian rough surface produced by Monte Carlo method are obtained.