【作者】 邢世其；

【导师】 王雪松；

【作者基本信息】 国防科学技术大学 ， 信息与通信工程， 2012， 博士

【摘要】 人造目标极化雷达三维成像理论和方法研究是极化雷达成像领域的前沿和热点问题，具有重要的理论意义和实用价值。论文立足于高分辨极化干涉SAR和极化层析SAR等典型的多维成像雷达体制，以军事侦察为主要应用背景，以提升极化成像雷达在军事侦察中的应用水平为目的，深入研究了SAR极化校准和人造目标的极化雷达三维成像的理论和方法。第一章阐述课题的应用背景和意义，归纳了极化成像雷达系统研究现状，总结了SAR极化校准与三维成像理论与方法的研究现状，最后介绍了本文的主要工作。第二章研究了SAR极化校准的新方法。在总结基于点目标和基于分布式目标的SAR经典极化校准方法的基础上，从理论推导和仿真实验两个层面对其性能进行了评估。首次发现并证明了经典Ainsworth校准方法估计的测量误差参数之间存在确定而不合理的关系。针对分布式目标散射不满足方位对称特性的情形，修正了经典SAR极化校准方法的假设条件，建立了一种能够保护目标取向信息的极化校准模型（TOP模型），并提出了求解TOP校准模型的快速迭代算法。此外，研究了TOP模型中取向角估计与测量误差参数估计之间的耦合特性，推导了取向角估计误差对测量误差参数估计的影响。最后利用机载极化SAR数据对基于TOP模型的SAR极化校准新方法进行了验证。第三章深入研究了人造目标极化干涉SAR三维成像方法。立足军事侦察应用背景，提出了针对两类典型人造目标的极化干涉SAR三维成像处理框架。在此基础上，围绕“多极化联合三维成像”以及“干涉成像的角闪烁抑制”两个关键问题，从极化超分辨成像和合成型散射中心检测两个方面展开了深入研究：首先建立了人造目标极化干涉SAR图像域和空间频率域信号模型，在此基础上提出了一种极化干涉SAR多通道联合超分辨特征提取方法M-ESPRIT，并通过实验研究了M-ESPRIT的性能；深入研究了多散射点层叠对干涉处理的影响，分四种情形推导了合成型散射点的干涉相位分布，在此基础上提出了一种基于多极化干涉相位差异的合成型散射中心检测方法，研究了检测性能与信噪比的关系；针对极化干涉处理中的相位跳跃问题，提出了基于特显点干涉相位对齐的解决方法；最后利用机载极化干涉SAR数据开展了两类人造目标的三维重建实验，对本文方法进行了验证。第四章深入研究了多基线极化层析SAR三维成像理论与方法。针对极化层析SAR非均匀基线型式，分别提出了基于虚拟阵列变换和Tikhonov正则化理论的极化SAR层析成像方法。从信号估计的角度证明了Tikhonov正则化方法在特定条件下是对目标散射“高度像”的最大后验概率估计，以奇异值分解为手段，建立了傅立叶分析、TSVD以及Tikhonov正则化方法的一致框架。针对非均匀基线条件下的人造目标超分辨三维成像问题，首次将分布式压缩感知理论引入极化层析SAR三维成像领域，提出了MMV-CS多极化联合超分辨层析成像方法，并针对压缩感知成像中的信号泄露问题，提出了一种基于滑动窗口的迭代抑制算法。利用仿真实验对不同极化层析成像算法的性能进行了检验。设计并开展了三维高分辨全极化层析成像实验，研究了平台抖动引起的相位误差对层析成像性能的影响，提出了一种基于特显点的相位校正方法，国际上首次获得角反射器和车辆目标的三维高分辨全极化层析成像结果，证实了本文提出的MMV-CS方法在超分辨和抗模糊方面的性能优势。第五章总结了论文的研究工作和主要创新点，对需要进一步研究的问题进行了展望。更多还原

【Abstract】 3-D reconstruction of man-made objects is an advanced issue in the area of polarimetricradar imaging, and is of great value both in theory and in applications. Aimed topromote the applications of polarimetric3-D imaging radar in military reconnaissance,this thesis studies the techniques including polarimetric SAR calibration and3-Dreconstruction of man-made objects in the background of polarimetric interferometricSAR (InSAR) and polarimetric tomographic SAR (TomoSAR).Chapter1illustrates the background and necessity of the research, briefly recallsthe development of polarimetric imaging radar systems, summarizes the previous worksin the related fields，and then gives a brief introduction of the major works in thisresearch.Chapter2studies the SAR polarimetric calibration techniques. After reviewingsome classical polarimetric calibration techniques based on point targets or distributedtargets, an in-depth performance study is presented through theoretical analysis andsimulation verifications. For the first time, it is found that there exist some definite butunreasonable relations between the estimates for the distortion parameters form theclassical Ainsworth calibration technique. For the case that the azimuth symmetryassumption widely adopted in the previous works does not hold, a calibration modelcalled TOP, which is capable of preserving the target orientation information, isproposed by considering the orientation angle shift effect on the measurement of targetscattering matrix. Then a fast iterative algorithm is proposed to solve the TOPcalibration model. In addition, the couple between the estimates for the orientation angleand the distortion parameters is studied, and the impacts of the error of orientation-angleestimate on the estimate for the distortion parameters are analyzed. Real collectedairborne SAR data are utilized to verify the effectiveness of the proposed model andalgorithm.Chapter3studies the3-D reconstruction of man-made objects using polarimetricInSAR. A processing scheme for the reconstruction of man-made objects of two kindsis presented firstly. Then, in-depth researches about two key topics, which are themulti-polarimetric joint3D imaging and the suppression of multiple scattererinterference, are presented. A super resolution technique (M-ESPRIT) for the jointextraction of scattering centers in polarimetric InSAR images is proposed, and theperformance of M-ESPRIT algorithm is checked by processing simulation data and theanechoic data. We derived the phase statistics for the interferometric phase of scatterers produced by the overlay of multiple elementary ones. A detection algorithm is proposedfor testing whether a scatterer is an elementary scatterer, and its performance versusSNR is presented. For the phase ambiguity problem, a phase alignment operation isrecommended. We demonstrate the effectiveness of the proposed techniques byperforming the3-D reconstruction of some targets using polarimetric InSAR data.Chapter4presents a thorough research on the3D tomographic imaging techniques.For the tomographic imaging in the case of irregular baseline distribution, twoalgorithms based on array transform technique and Tikhonov regularization technique,respectively, are proposed. We show from the statistical point that the Tikhonovregularization method is actually a MAP estimate for the height profile in someparticular cases. A united framework incorporating the FFT, TSVD and the Tikhonovregularization method is presented. For the first time, the distributed compressivesensing technique is introduced into the polarimetric SAR tomography application,producing the MMV-CS super resolution tomographic imaging technique. A fastimaging algorithm is proposed for the MMV-CS model, and the signal leakage problemis tackled with a window-based iterative algorithm. Simulations are performed to checkthe effectiveness of the proposed algorithms. The3-D full polarimetric tomographicimaging experiment is carried out. We demonstrate that the impact of the phase errorinduced by an array element error on the tomographic imaging, and propose acalibration technique employing prominent scatterers to adapt the3D imaging methodto practice. For the first time, the3D reconstruction results of a vehicle and cornerreflectors are obtained, and the results verify the advantages of the proposed MMV-CSmethod in terms of super resolution power and ambiguity level. Chapter5summarizesthe research work and main innovations, and discusses the future work.更多还原