【作者】 刘皊皊；

【导师】 李勇；

【作者基本信息】 南京航空航天大学 ， 通信与信息系统， 2009， 硕士

【摘要】 本文对具有重要军事应用价值的机载三通道合成孔径雷达(SAR)地面动目标指示(GMTI)技术的基本原理、算法流程和实现方案进行了较为全面的研究。文中,特别针对存在未知通道幅相误差的情况,研究了四种通道误差校正方法,给实际系统条件下如何提高系统性能提供了有价值的参考。第一章为绪论,概述了国内外机载雷达动目标指示技术的发展历程和研究现状,阐述了本文的研究意义和研究内容。第二章建立了SAR目标回波模型,对目标运动引起的多普勒参数变化及其对SAR成像处理的影响进行了理论分析和点目标仿真验证,为后续研究杂波抑制干涉,实现动目标检测提供理论基础。第三章研究了基于杂波抑制干涉处理的机载三通道SAR/GMTI的基本原理和算法流程,并结合点目标仿真数据验证了理想情况下算法的有效性,给出了动目标检测性能的定量分析结果。第四章主要针对实际系统存在的各种通道幅相误差,以及校正算法进行了研究。通道间幅相误差是导致SAR/GMTI系统杂波抑制性能下降的一个主要因素,本章对导致通道幅相误差的各类因素进行了分析,并重点研究了四种通道均衡算法。这些方法分别在图像域以及两维频域对通道误差进行校正。文中通过仿真实验以及对实测数据的处理结果验证了这四种算法的有效性。第五章推导了干涉SAR/GMTI技术对动目标的检测和定位性能,给出了三通道杂波抑制干涉SAR/GMTI方案的检测概率和定位误差等曲线,并进行了深入的仿真研究。第六章对全文工作进行了总结,指出了有待进一步研究的问题。更多还原

【Abstract】 In this thesis, the algorithm and implementation methodology for the three-channel airborne SAR/GMTI technique, which is of great value in military application, are studied in detail. Some methods are particularly analyzed in order to correct the unknown phase and amplitude errors among different channels which worsen the performance of a live system. The conclusions obtained from this research provide a valuable reference for improving the system performance under actual conditions.Chapter 1 is the brief introduction. The history of SAR and GMTI technology are firstly outlined and then the background and main contents of this research are addressed.Chapter 2 firstly investigates the signal model of moving targets echoes. Then, the impacts of Doppler parameters of moving target on the SAR imaging processing are discusses in detail. At last, the point-target simulation results are also given to validate and lay down the basis for the following studies.In chapter 3, the realization flowchart for three-channel airborne SAR/GMTI radar based on the clutter suppression interferometry technique is firstly discussed. The point-target simulation then verifies the effectiveness of the algorithm in the case of an ideal condition. At last, the quantitative performance of moving target detection is also analyzed in the text.In chapter 4, the phase and amplitude errors between different receiving channels which are considered to be primary factors worsening the performance of clutter suppression are discussed in detail, followed by the investigation of four calibtration algorithms. These algorithms calibrate various kinds of errors in different domains, i.e. image and 2D frequency domain. Simulation and experimental clutter suppression results are employed to verify the virtue of these algorithms.Chapter 5 analyzes the performance of the above mentioned three-channel interferometric SAR/GMTI scheme according to the detection probability and the relocation accuracy for slowly moving targets. Detailed simulations of the three-channel SAR/GMTI are performed in the text.In chapter 6, the work is concluded and the possible problems to be further researched are also pointed out.更多还原