利用升降轨SAR数据提取地震三维同震形变场中模型的完善与实现

发布时间：2019-04-19 23:14

【摘要】：合成孔径雷达干涉测量技术(Interferometrv Synthetic Aperture Radar, InSAR)在近二十年来得到了迅猛发展,在获取地面形变信息具有独特的优势,使得人类从外空间对全球地表进行长时间大范围的监测成为可能。但是,InSAR测量获取的只是地表形变沿雷达视线向(LOS)的分量,不能全面地反映地表真实变形,即存在InSAR的视线向模糊问题。尤其是对于地震、火山喷发等大形变,需提取地表的三维形变特征,以迅速获取灾害信息、提供救援以及更加准确分析发震构造与地震机理。本文在总结和分析了几种利用InSAR提取三维形变的方法的基础上,完善了用升降轨SAR数据提取三维形变场的计算模型,并选取意大利拉奎拉为研究区,运用ENVI、 SARscape和Matlab等软件平台予以具体实现。实现过程主要分为两部分：(1)分别利用常规D-InSAR和多孔径雷达干涉测量(Multiple Aperture InSAR, MAI)对升降轨SAR数据进行处理,得到研究区沿雷达视线向和方位向的形变信息；(2)用加权最小二乘原理(Weighted Least Square, WLS)对上述两种形变进行融合计算,获取研究区地表在上(U)、北(N)、东(E)三个方向上的形变,即三维同震形变场。本论文主要成果如下： (1)完善了利用升降轨获取地表三维形变的计算模型,对于SAR所有可能的获取模式——左视升降轨、右视升降轨四种情况分别进行了分析研究,推导出了每种情况的三维形变量计算公式,并总结出了通用表达式； (2)解决了升、降轨数据融合中的关键问题——重合区域求取； (3)运用完善后的计算模型,成功提取了2009年4月6日意大利拉奎拉地震的三维同震形变场。结果显示,此次地震在竖直方向、南北方向和东西方向均发生了位移,其中以竖直方向最为明显,最大位移为16.8cm；地表沿断层面发生了明显的错动,其中西南盘为下降盘,向西北方向滑动,东北盘为上升盘,向东南方向滑动,综合结果可得到断层为右旋走滑断层,与地质调查结果一致。
[Abstract]:Synthetic Aperture Radar Interferometry (Interferometrv Synthetic Aperture Radar, InSAR) has been developed rapidly in the past two decades, and it has a unique advantage in obtaining ground deformation information. It is possible for humans to monitor the global surface from outer space for a long time and on a large scale. However, InSAR measurements only obtain the component of the surface deformation along the radar line-of-sight (LOS), which can not fully reflect the true deformation of the surface, that is, the blurring problem of the line-of-sight of InSAR exists. Especially for large deformation, such as earthquake, volcanic eruption and so on, it is necessary to extract the three-dimensional deformation characteristics of the surface in order to obtain disaster information quickly, provide rescue and more accurate analysis of seismogenic structure and earthquake mechanism. On the basis of summarizing and analyzing several methods of extracting three-dimensional deformation by InSAR, this paper consummates the calculation model of extracting three-dimensional deformation field by lifting rail SAR data, and selects L'Aquila, Italy, as the study area, and uses ENVI, as the research area. The software platform such as SARscape and Matlab is implemented in detail. The realization process is divided into two parts: (1) using conventional D-InSAR and Multi-Aperture Radar Interferometry (Multiple Aperture InSAR, MAI) to process the SAR data of the lift and fall orbit, and get the deformation information along the line of sight and azimuth of the radar in the study area; (2) the weighted least square principle (Weighted Least Square, WLS) is used to calculate the above two kinds of deformation, and the deformation of the surface of the study area is obtained in three directions of the upper (U), north (N), east (E), that is, the three-dimensional coseismic deformation field. The main achievements of this paper are as follows: (1) the calculation model of three-dimensional deformation of the ground surface obtained by lifting rail is improved, and all possible acquisition modes of SAR-left-looking lift-rail and right-looking-lift-rail are analyzed and studied respectively. The calculation formula of three-dimensional shape variables in each case is deduced, and the general expression is summarized. (2) the coseismic deformation field of the L'Aquila earthquake, Italy, on April 6, 2009 has been successfully extracted by using the improved computational model, which is the key problem in the data fusion of the ascending and descending orbit, namely, the coincident region finding; (3) the coseismic deformation field of the L'Aquila earthquake on April 6, 2009 has been successfully extracted. The results show that the displacement occurred in the vertical direction, the north-south direction and the east-west direction, in which the vertical direction is the most obvious, the maximum displacement is 16.8cm; There is obvious dislocation along the fault plane, in which the southwest disk is the descending disk, sliding to the northwest, the northeast plate is the rising disk, and moving southeast, the comprehensive result shows that the fault is the right-lateral strike-slip fault, which is consistent with the geological survey results.
【学位授予单位】：首都师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P225;P227

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