三维随机粗糙海面与舰船的复合电磁特性的高频方法分析研究

Study on Efficient High Frequency Method of Electromagnetic Scattering from Ships above Sea Surface

3维随机粗糙海面与其上方复杂目标复合电磁(EM)散射特性的建模与分析在微波遥感、目标识别、雷达成像、导弹制导等领域中有着重要的研究价值。该文主要研究了基于高频算法的随机粗糙海面及舰船的复合电磁散射特性,开发了PO-IPO混合方法,为3维随机粗糙海面与复杂目标一体化高效求解提供了新思路。文中分别使用了物理光学方法(PO)、迭代物理光学方法(IPO)、PO-PO以及PO-IPO混合方法对海面及舰船进行了建模与仿真,其中,引入锥形波来代替平面波作为发射源,锥形波可以更好地抑制粗糙面在边缘位置被突然截断而形成的电磁反射和边缘绕射等效应。从数值仿真结果中可以看出,PO-IPO混合方法可将复杂物体本身面元间以及粗糙海面与物体间的耦合作用考虑在内,因此PO-IPO可以作为一种有效的途径来快速获取随机粗糙海面及舰船的复合电磁散射特性。

The study on the composite ElectroMagnetic(EM)scattering characteristics of electrically large ships over a random rough surface is significant in the fields of microwave remote sensing,target recognition,and radar imaging.In this paper,an efficient PO-IPO hybrid method is proposed to analyze the scattering from complex targets over the sea surface.The PO method can be used to analyze the scattering from an electrically large sea surface.However,low accuracy will be achieved for targets with complex structures.Therefore,the IPO is applied for computation herein.In the numerical results,several high-frequency methods(PO,IPO,PO-PO,and PO-IPO)are used to analyze the scattering characteristics of targets over the sea surface.Notably,the tapered wave is used as the source in the numerical results,which can restrain the EM reflection and edge diffraction.The results also indicate that the proposed PO-IPO can be used as an efficient tool to obtain the scattering characteristics of complex targets over the sea surface.