基于HPP/PO的舰船与海面耦合散射快速算法

针对粗糙海面上舰船类超电大尺寸复杂目标电磁散射问题,提出了一种基于混合面元投影(HPP)和物理光学法(PO)的计算目标与海面耦合散射的快速算法。首先建立基于海谱的海面几何模型,并考虑海面面元的微粗糙特性,修正海面反射系数,然后针对目标和海面的结构特点,形成两种尺度面元混合的目标与海面模型,对电磁波在海面和目标之间的多次反射按照GO原理进行快速投影运算,并利用PO计算投影区域的散射贡献,最后给出了几组典型实例的计算结果。数值计算表明,该方法对于海面舰船类目标的散射计算是高效、准确的。

Fast algorithm based on HPP/PO for calculating coupling EM scattering from ship over sea surface

In order to study the electromagnetic(EM) scattering from rough sea surface with presence of an electrically large complex target such as warship,an efficient algorithm based on hybrid patch projection(HPP) and physical optics(PO) method is proposed to calculate the coupling scattering of the target and underlying sea surface.Sea surface models composed by planar patches are simulated based on sea-spectrum,and the small roughness of each patch is taken into account by modifying the Fresnel reflection coefficients of planar sea surface.Considering the configuration characteristics of ship and sea surface,a two-scale-patch model is formed for fast projection operation to determine the projective area using geometrical optics(GO) theory to trace multiple reflected rays between target and sea surface,and the scattering of projective area is finally calculated by using PO method.The high efficiency and preciseness of the proposed method are verified by numerical results,which would be especially valuable in engineering application.