海面舰船目标SAR图像仿真的电磁散射机理和模型研究

Based on the electromagnetic(EM) scattering mechanism and model, the defects that Synthetic Aperture Radar(SAR) system can hardly obtain the measurement results caused by all kinds of restriction conditions can be made up by SAR image simulation of actual complex sea surface. In combination with the measurements, SAR image simulation can provide effective ways and database resources for image interpretation and target recognition. Through the investigation of scattering mechanism and model in SAR image simulation technology, the interaction mechanism between the electromagnetic wave and targets in SAR imaging can be better comprehended. And, the extraction method of electromagnetic scattering characteristics also can be get further developed. According to the deterministic facet-based scattering model of dynamic sea surface and the hybrid algorithm, the combination of the method of equivalent currents(MEC) with the facet-based method and the multi-path model that used to deal with the composite scattering of targets and sea surface, this project aims at the spaceborne and airborne SAR imaging radar system to focus on solving such a scientific problem that the applications of the EM scattering mechanism to the SAR image simulation and the feature analysis. Through the simulation of the SAR imagery echo data, the investigation of SAR image algorithm for dynamic sea surface compound with ships and the method of auxiliary feature extraction can provide necessary theory and new method for the remote sensing of the sea surface, the target feature extraction and environmental monitoring, especially for the in-depth study on the high resolution observation technology.

基于电磁散射机理和模型的动态海面复杂目标的SAR图像仿真，可以有效弥补SAR系统因受各种条件制约而无法获得测量结果的缺陷。同时，结合测量，仿真SAR图像可以为图像理解和目标特征识别提供有效方法和数据库资源。通过SAR图像仿真中的电磁散射机理和模型研究，可以更好地理解SAR图像中电磁波与目标的相互作用机理，促进目标电磁散射特征提取方法的研究。项目将针对星载和机载SAR成像雷达系统，利用动态海面的解析单元散射模型和海上目标复合散射的"等效流+单元法+多路径"新模型，重点解决电磁散射机理在SAR图像仿真和特征分析中应用的科学问题。并通过仿真SAR成像的回波数据，开展动态海面与舰船目标复合SAR成像算法和辅助特征分析研究，为海面目标遥感和目标特征提取、环境监测，特别是对地高分辨观测等技术深入研究提供必要的理论基础和新方法。

海洋环境舰船目标合成孔径雷达（SAR）成像的电磁散射机理和模型研究，是提高雷达探测系统性能、成像算法和提取目标特征的重要途径，也是国家海洋安全需求中亟待解决的应用基础问题。.本项目主要研究内容和创新成果如下：.1. 开展了近岸和深海海洋环境电磁散射特性研究。突破了传统数值方法和双尺度模型对随机相位分布描述和应用的局限性，提出了包括布拉格散射和海浪的非线性特征的大场景海面的优化面元散射模型。.2. 开展了海洋环境舰船目标的复合电磁散射建模研究。突破了传统多路径模型中对随机粗糙海面反射场的不准确描述和应用的局限性，提出了动态海面与目标复合电磁散射的加权多路径复合散射模型、基于物理光学-几何光学的优化面元散射模型和基于六自由度舰船随海浪运动的复合散射模型。.3. 开展了基于电磁散射机理和模型的海面目标雷达成像方法研究。提出了能够更准确描述动态海面运动舰船目标的成像雷达的频域宽带信号仿真模型，完成了多种海情的动态海面与舰船目标复合场景的SAR成像回波数据仿真。.4. 开展了电离层对星载SAR成像质量影响的模型补偿方法和目标识别算法研究。.基于本项目，课题组主编了专著2部，发表了35篇SCI检索论文，其中在本领域国际顶级期刊Journal of Geophysical Research、IEEE Transactions on Geoscience and Remote Sensing和IEEE Transactions on Antennas and Propagation上发表论文12篇。在动态海面的统计特征描述、动态海面与复杂目标复合电磁散射和SAR成像仿真模型的建立方面，填补了多项国内空白，为海面目标遥感、特征提取和环境监测的深入研究，提供了必要的理论依据和支持。