雷达遥感在地震监测中的应用研究

发布时间：2018-04-22 03:00

本文选题：玉树地震 + 差分干涉测量　；参考：《西安科技大学》2017年硕士论文

【摘要】：地震被认为是一种由地壳力学机制引起的自然现象,是给人来带来影响最大的自然灾害之一。本文首先对InSAR形变测量原理进行了介绍,将PALSAR雷达传感器获得的玉树地震前后的雷达影像作为原始资料数据,然后在两轨差分干涉测量方法的基础上,对主从影像进行差分干涉处理,最终得到研究区域在雷达视线向上的地表形变。在处理过程中对数据选取、配准、重采样、滤波、相位解缠、轨道精炼、地理编码等一系列问题进行研究分析。考虑到需要提高地表同震形变场的精度,本文在处理过程中使用Goldstein滤波来对差分干涉图进行滤波处理,并建立线性回归模型对大气相位进行去除。结果表明玉树地震区域的形变范围为-0.58m-0.37m,并且玉树地震区域西南部分为沉陷形变,东北部分为抬升形变。本文在震源参数反演的过程中引入了Okada位错理论相关模型。假设在断层均位于弹性半空间均匀介质中的前提条件下,详细介绍了点源位错形变与应变模型以及有限矩源位错形变与应变模型建立的方法。同时假设在断层滑动为均匀滑动的情况下,对断层几何参数反演方法进行了解释,并以此为理论基础,将获得玉树地震地表同震形变场作为约束数据,对玉树地震的断层几何参数进行了非线性反演,其结果与CMT公布的结果基本拟合。在对断层的滑动量进行线性反演的过程中,将上一步得到的断层几何参数作为已知数据,最终获得研究区域的断层滑动分布。并以此计算了玉树地震的震源参数,得到其矩张量为:,对应的矩震级为,与CMT公布的结果基本保持一致。为验证玉树地震断层滑动反演的准确度,最后对反演结果进行正演处理,得到了玉树地震区域的正演形变场。将该形变场与通过PALSAR雷达影像获得的形变场进行比较。需注意,由于断层滑动反演过程中对地表同震形变场进行了降采样处理,形变区域选取的采样点远远多于其他区域。因此在对形变场进行比较时,主要在形变区域进行选点比较。最后比较结果显示,形变场的差值基本在±10mm之内。
[Abstract]:Earthquake is considered to be a natural phenomenon caused by the mechanical mechanism of the earth's crust. It is one of the most important natural disasters. Firstly, the principle of InSAR deformation measurement is introduced. The radar image of the Yushu earthquake before and after the PALSAR radar sensor is used as the original data, and then the two track differential interferometry is used. On the basis of the method, the main and subordinate image is processed by differential interference, and the surface deformation of the area on the radar line of sight is finally obtained. In the process of processing, a series of problems such as data selection, registration, resampling, filtering, phase unwrapping, orbit refining, and Geo coding are studied and analyzed. Considering the need to improve the surface deformation field of the surface In the process of processing, this paper uses Goldstein filtering to filter the differential interferogram and sets up a linear regression model to remove the atmospheric phase. The result shows that the deformation range of the Yushu earthquake region is -0.58m-0.37m, and the southwest part of the Yushu earthquake region is the subsidence deformation and the northeast part is the uplift deformation. In the process of seismic source parameter inversion, the Okada dislocation theory model is introduced. Assuming that the fault is located in the elastic half space homogeneous medium, the method of the dislocation deformation and strain model of point source and the method of establishing the dislocation deformation and strain model of the finite moment source are introduced in detail. In addition, the inversion method of geometric parameters of the fault is explained. On this basis, the ground surface deformation field of the Yushu earthquake will be taken as the constraint data, and the geometric parameters of the fault of the Yushu earthquake are nonlinear inversion. The results are basically fitted to the results published by the CMT. The linear inversion process of the slip of the fault is carried out. In this way, the fault geometric parameters obtained in the last step are given as known data, and the fault slip distribution in the study area is finally obtained. In addition, the source parameters of the Yushu earthquake are calculated and the moment tensor is obtained. The corresponding moment magnitude is consistent with the results published by the CMT. In order to verify the accuracy of the fault slip inversion in the Yushu earthquake, the final accuracy is verified, finally, the accuracy of the fault slip inversion is verified. In the forward processing of the inversion results, the forward deformation field of the Yushu seismic region is obtained. The deformation field is compared with the deformation field obtained through the PALSAR radar image. It is necessary to pay attention to the reduction of the ground surface deformation field in the process of the fault slip inversion, and the sampling points in the form area are far more than the other regions. Therefore, when comparing the deformation field, the main points are compared in the deformation area. Finally, the comparison results show that the difference of the deformation field is basically within the range of + 10mm.

【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P315.7

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