【作者】 王永强；

【导师】 朱岱寅；

【作者基本信息】 南京航空航天大学 ， 信号与信息处理， 2009， 硕士

【摘要】 近年来,地面运动目标检测和成像是合成孔径雷达(SAR)领域中的一个研究热点,无论在军事上还是在民用中都具有非常重要的意义。本文主要研究了机载多通道合成孔径雷达地面动目标指示技术,并在通用数字信号处理系统上实现了实测数据的慢动目标检测处理。本文所做工作包含以下几方面:论文第一章回顾了合成孔径雷达地面动目标指示技术(SAR/GMTI)的研究背景及现状,介绍了数字信号处理器(DSP)在雷达信号处理中的应用,并概括了全文的主要内容。第二章首先建立运动目标的SAR误差谱模型,然后推导了运动目标经过极坐标格式算法(PFA)处理后的误差谱表达式,在此基础上,通过对运动目标误差谱的讨论,给出了PFA算法完整的动目标响应特征(包括目标几何定位误差、残留距离徙动以及散焦特性)分析。最后通过仿真对理论分析结果进行了验证。第三章对基于特征值分解的双通道地面慢动目标检测方法进行了详细描述。仿真及实测数据实验结果表明:利用特征分解得到的第二特征值可以有效地实现SAR图像上的慢动目标的检测。接着通过超分辨方法(Superresolution Method)对已检测到的慢动目标进行定位和测速,并分析了影响定位、测速精度的因素,如目标信噪比、估计杂波协方差矩阵的样本数等。第四章首先对和/差波束干涉SAR/GMTI技术进行了详细的理论分析,然后进行了和/差波束干涉SAR/GMTI技术的性能分析。实测数据处理结果表明,和/差波束干涉SAR/GMTI技术可以实现对淹没在强杂波背景中的慢速动目标的检测、测速和定位。第五章研究了在通用数字信号处理硬件系统上实现以上SAR/GMTI算法的途径。通过第三和第四章的讨论,对双通道SAR/GMTI以及和/差波束干涉SAR/GMTI处理任务进行并行设计,在通用数字信号处理系统上实现了地面慢动目标检测算法的并行处理,并给出了实测数据的检测结果。第六章:对全文工作进行了总结,并指出下一步需要继续研究的问题。更多还原

【Abstract】 In the recent years, ground moving target detection and imaging has become a hot topic in the field of Synthetic Aperture Radar (SAR), and has been highly valuable for both military and civilian application. This dissertation mainly studies multi-channel SAR/GMTI techniques, and the GMTI processing of the measured data is implemented on general digital signal processing system.The main work of this dissertation is as follows:In chapter 1, firstly, we review the research background and current situation of SAR/GMTI technique. Secondly, the applications of DSP technology in radar signal processing is introduced briefly. Finally, the main contents of the dissertation are addressed.In chapter 2, the SAR image-error-spectrum model of the moving target is firstly defined.Then, the image-error-spectrum after the PFA processing is derived. On the basis of the image-error-spectr- um, detailed analysis on the SAR signatures of moving target, including the geometric displacement, residual range migration, and the defocusing effect in both range and azimuth dimensions is performed. Finally, the simulation results validate the theoretical analysis.In chapter 3, an effective dual-channel SAR/GMTI method based on eigen-decomposition of sample covariance matrix is investigated in detail. Numerical experiments on simulated data and measured data are presented to show that the second eigenvalue after eigen-decomposition of the sample covariance matrix can be applied to detect moving targets effectively. Subsequently, the radial velocity and relocation of the detected target are estimated by superresolution method. At the same time, we analyze the factors that affect the accuracy of the estimated velocity and relocation, including the signal noise ratio and the number of samples in the covariance estimation.In chapter 4, firstly, theΣ/Δbeam interferometric SAR/GMTI technique is theoretically analyzed. Then, the performance analysis of theΣ/Δbeam interferometric SAR/GMTI is presented. Finally, the measured data processing confirms that the slow-moving targets masked in clutter can be detected via this technique, while the radial velocity and relocation of the detected target are estimated.In chapter 5, it is studied that the implementation of aforementioned SAR/GMTI algorithms on general digital signal processing system. In the light of the detectable algorithm and the hardware recourse of the system, after the parallel division of the processing tasks in chapter 3 and 4, the parallel processing of the ground slow-moving target detection algorithm is realized on general digital signal processing system, and the resulting detection of the measured data is given.In chapter 6, the work of this dissertation is concluded and the further research is also pointed out.更多还原