【作者】 杨秋玲；

【导师】 苗放；

【作者基本信息】 成都理工大学 ， 地球探测与信息技术， 2011， 硕士

【摘要】 随着空间信息技术特别是雷达遥感技术的发展,合成孔径雷达干涉测量(Interferometric Synthetic Aperture Radar,InSAR)技术得到了迅速发展。近年来在InSAR基础上发展起来的差分雷达干涉测量(Differential Interferometic SAR,D-InSAR)技术对于地表形变的变化非常敏感,且监测精度较高(毫米级),加上它具有全天候、范围广、成本低等独特优势,已经越来越广泛地应用于地表形变监测中。然而在实际应用中,由于受到雷达系统自身成像几何限制、系统热噪声去相干、时间去相干以及空间基线去相干等诸多因素的影响,SAR影像常常发生几何畸变,生成的干涉条纹图相干性较低,常常出现不连续或跳跃现象,这些都使得最终获得的地表形变量精度与理论值相差甚远。因此,本文对InSAR/D-InSAR数据处理过程的最关键步骤之一----相位解缠技术进一步研究,使得这项技术更好地应用到地面沉降监测应用中,这是值得深入研究的热点和前沿技术问题,具有较强的现实意义和科学价值。本文对干涉雷达技术相关的文献进行了全面检索与分析,较为全面详尽地介绍了相位解缠技术的国内外研究现状和InSAR技术基本原理;详细介绍了现有的各种InSAR相位解缠算法,比较各种算法的优缺点并分析其适用性,对其中适合在实际InSAR相位解缠中应用的算法进行了仿真实验;在总结分析相位解缠阻扰因素的基础上,提出了一种针对不连续干涉条纹图的相位解缠方法,并成功应用于汶川震区的地表形变监测中。取得的主要成果如下:⑴提出了一套针对低相干性不连续干涉条纹图的相位解缠阻扰因素分析方法。这种分析方法全面考虑了雷达侧视成像模式影响下的SAR图像几何畸变以及各种去相干源等因素对相位解缠的精度及效率的影响;⑵提出了一种在控制点等先验知识指导下对不连续干涉条纹图进行相位解缠的方法。这种方法的提出是以全面分析相位解缠阻扰因素为基础的,它的提出实现了面向应用可靠性需求的相位解缠。采用这种方法对汶川震区的低相干性不连续干涉条纹图进行相位解缠实验,并将其解缠结果与采用其他三大类解缠算法的结果进行对比,通过分析各种算法的解缠精度,结果表明,对低相干性不连续干涉条纹图,采用文中所提出的这种解缠方法得到的结果相对比较理想。更多还原

【Abstract】 With the development of spatial information technology, especially the development of radar remote sensing technology, the Interferometic Synthetic Aperture Rader (InSAR) technique has flourished. In recent years, Differential Interferometic SAR (D-InSAR), developed on the basis of InSAR, which is sensitive to the change of topography has been more and more popular in monitoring topography-displacement for its high precision measurement in displacement-field, plus it is all-weather, fargoing and low-cost, etc. However, SAR images always have geometric distortion and the lower coherence, and the resulting interference fringes aren’t continuous or occur jumps in practical application because of the geometric constraints of imaging radar, thermal noise decoherence, time decoherence, spatial baseline decoherence etc., which lead to the ultimately accuracy of surface deformation far with the theoretical value. Therefore, this paper further study the phase unwrapping thchnology that is one of the most critical steps of InSAR/D-InSAR data processing, making better use of this technology to the land subsidence monitoring applications. It is a further study hot spots and leading-edge technology and has obvious practical significance and scientific value.This paper proceeds search and analysis to literature of Rader Interferometry; descriptions the phase unwrapping technology comprehensivly and the basic principles of InSAR technology; explains the various existing InSAR phase unwrapping algorithm; compares the advantages and disadvantages and the applicability of various algorithm; conducts simulation experiment to InSAR algorithm which is suitable for actual application. The author proposes a phase unwrapping method targeted to interference fringe pattern of discontinuous images, and apply to the earthquake ground deformation monitoring of WenChuan earthquake. Main achievements are obtained as follows:(1) Put forward a set of phase unwrapping obstruction of factor analysis to low-coherence interferogram discontinuous images. The method analyses geometric distortion of SAR images under the influence of radar side-looking imaging mode and the accuracy、efficiency of the phase unwrapping under the influence of various decoherence.(2) Put forward a method to phase unwrapping of discontinuous interference frige images under the direction of priori konwledge of the control points, and achieve the reliability requirements for the application. This method based on analysising the obstruction of factors of phase unwrapping will be applied to the discontinuous interference frige images of the WenChuan area, and compare the results with those results of other phase unwrapping methods. It finds that the result which is by the unwrapping algorithm to the discontinuous low-coherence interference fringes images is ideal.更多还原