陆海交界区域舰船电磁散射特性与耦合机理分析

Due to the feature of shallow water, electromagnetic wave penetrable, ground-ocean junction, the detection and identification of target located in near shore area has always been a difficult question in the field of radar technology. In view of the urgent demand of the down looking radar for the radar signature of target located in near shore area, this project denoted to exploit the electromagnetic scattering properties and coupling scattering mechanism of a three dimensional warship located on ground-ocean junction composite surface. Specially, a layer sea surface (with the upper layer of water and lower layer sand) and a ground-ocean junction composite surface is established with a high degree of accuracy. During which, the submarine topography and the coastline shapes are considered. The hybrid method FMM-PO-SSA-II and PO-PO-SSA-II are adopted to build the model of composite scattering from warship (medium and small electrical size) located on composite surface. And a CS based hybrid method is proposed for the purpose of breaking through the key technology in solving scattering problems from an electrically large size warship located on large scale composite surface. The coupling scattered field is obtained by induced current decomposition method. Based on this, the influence of the parameters of radar, sea state, target and coastline types on the composite scattering properties is studied. And the coupling scattering mechanism between the warship and the ground-ocean junction composite surface are revealed. The multi-parameter models, that affecting the coupling scattering between the warship and the ground-ocean junction composite surface, are built. This project will provide a theoretical basis and a technical support for the shore-based radar performance evaluation, clutter suppression of the ground-ocean junction area, etc.

濒海区域具有海水浅、电磁波可穿透、陆海共存等特点，因此对该区域的目标检测、识别一直是雷达技术领域的难点问题。鉴于下视雷达对濒海区域目标特征信号的迫切需求，本项目拟开展三维陆海交界复合型粗糙面与舰船电磁散射特性与耦合机理分析研究。具体包括考虑海底地形及海岸线的影响，建立浅海上层海水、下层沙石分层海面起伏模型及三维高精度陆海交界复合型粗糙面几何模型；采用SSA-II与FMM-PO、SSA-II与PO-PO的混合方法建立复合型粗糙面与中小电尺寸舰船电磁散射模型；突破大区域复合场景与电大尺寸舰船电磁散射关键技术，形成基于压缩感知的快速混合方法；进而利用感应电流分解法提取耦合散射场，通过分析雷达、海况、目标参数及海岸线类型对耦合散射的影响，揭示复合型粗糙面与舰船耦合散射机理，建立影响陆海交界复合型粗糙面与舰船耦合散射的多参数关联模型，为岸基雷达性能评估、陆海交界区域杂波抑制等提供理论依据和技术支撑。

下视雷达对处于复杂环境中的目标进行探测时需要精确去除环境回波及环境与目标间的耦合回波。当下视雷达对处于濒海区域舰船目标进行探测时，一方面由于海浪受浅水效应、有限风区、海底摩擦、海岸反射等的影响，濒海区域海面起伏特性与深海不同；另一方面由于该区域具有海水浅、电磁波可穿透、陆海共存等特点，造成濒海区域背景雷达回波、背景与目标耦合散射机理与深海区域、内陆区域均不同。因此依据深海及内陆起伏模型所得背景与目标耦合作用机理无法满足濒海区域下视雷达目标检测及预警需求。复杂陆海交界区域耦合散射机理的空缺，与用户的迫切需求形成了突出的矛盾。.本项目针对上述矛盾在已有地海面几何建模理论基础上，提出了加权反正切函数，用于平滑连接地面区域与海面区域，形成了陆海交界复合型粗糙面；在已有目标与地海背景复合电磁散射理论基础上，采用SSA-II及SBR-PTD的混合方法建立复合型粗糙面与中小电尺寸舰船电磁散射模型；基于OpenMP、MPI、CUDA等的计算机并行加速技术，突破大区域复合场景与电大尺寸舰船电磁散射关键技术，形成快速混合方法，实现了陆海交界复合型粗糙面与真实舰船目标电磁散射快速求解；进而利用感应电流分解法提取耦合散射场，通过分析雷达参数（频率、入射角、极化方式等）、海况参数（风速、风向等）、目标参数（目标尺寸、位置、姿态、速度等）对耦合散射RCS、HRRP、多普勒频谱特征的影响，揭示复合型粗糙面与舰船耦合散射机理，为岸基雷达性能评估、陆海交界区域杂波抑制等提供理论依据和技术支撑。.项目研究期间在IEEE Trans. AP、AWPL等国内外著名期刊发表论文10篇(其中国际刊物8篇)；发表会议论文13篇(其中国际会议8篇)；获授权国家发明专利1件，申请国家发明专利5件。项目完成的同时，项目负责人获西安电子科技大学校优秀博士论文，第五届研究生创新成果展三等奖（排名第三）。