【作者】 范洪冬；

【导师】 邓喀中；

【作者基本信息】 中国矿业大学 ， 大地测量学与测量工程， 2010， 博士

【摘要】 矿产、地下水等资源开采引起的地面沉降已成为困扰社会和经济发展的普遍性难题。如何有效地、实时地监测地表沉降的发生,以分析沉降形成机理及演变规律、控制或减轻沉降灾害,是摆在国内外众多科研工作者面前的一个任务。本文从先进的对地观测新技术InSAR着手,首先分析了该技术用于地表沉降监测中的原理和局限性;然后对一些关键算法进行了改进和实验研究;最后利用D-InSAR、PS-DInSAR、SBAS等技术对天津市的失水沉降及某矿的开采沉陷监测进行了实验研究。本文的研究工作和成果如下:(1)总结了InSAR技术的研究现状,指出了国内外在InSAR及相关技术研究中的不足,阐述了SAR、InSAR、D-InSAR等技术的基本原理,分析了D-InSAR技术在沉降监测应用中的局限性。(2)研究了一种基于精密轨道参数、快速傅立叶变换及地面控制点的组合基线估计方法,并分析了偏斜角对基线估计精度的影响。通过对比分析不同基线组合方法生成的干涉条纹图及样本点高程值,验证了该组合基线估计方法的正确性及可行性,可在一定程度上弥补单一基线估计方法所存在的不足。(3)提出了结合边缘信息的DT-CWT干涉图滤波方法,并设计了相应的处理流程。该法利用DT-CWT域中层间系数的传递性和层内系数的相关性,得到干涉图的边缘及非边缘系数,并采用贝叶斯收缩或双变量贝叶斯收缩函数去噪,在去除噪声的同时,有效地保留了干涉图的边缘和细节信息。(4)提出了基于混合微粒群算法和改进的最小二乘相位解缠方法,并同十种常用相位解缠方法进行了实验对比分析,证明了算法的正确性。(5)建立了承压水位、地下水开采量同D-InSAR技术得到的沉降速率之间的关系模型,并对矿区开采沉陷进行了实验研究。为在一定程度上解决D-InSAR得到的开采沉陷下沉值小于实测值的问题,从控制点修正、多视处理两方面研究了两种针对开采沉陷应用的分析方法。(6)提出了基于正切函数加权的最优相干主影像选取方法,并提出了基于影像幅度和相位信噪比的双重阈值PSC识别方法,这些算法都可以作为现有方法的一个补充。(7)利用PS-DInSAR和SBAS方法获取了天津主城区1992-1997年间的地表下沉情况,前者共识别了18906个PS点,得到每年的最大下沉速率为16.4mm/a;后者共识别出42041个高相干点,得到每年的最大下沉速率为24.2 mm/a。利用SBAS方法初步获取了某矿1995-1998年间的地表下沉情况,共识别出380个高相干点,得到每年的最大下沉速率为45 mm/a。该论文有图63幅,表18个,参考文献165篇。更多还原

【Abstract】 Land subsidence caused by coal mining, groundwater over-exploitation and so on, has become a serious problem for the development of society and economy. Therefore, many researchers are faced with a difficult task, which is how to monitor the land subsidence effectively and timely, analyze the formation mechanism and evolution law of subsidence, and provide technical support for the control of disaster. In this dissertation, a new advanced technique of earth observation, called InSAR (Interferometric Synthetic Aperture Radar), was studied in detail. Firstly, the basic principle and limitation of this technique was analyzed. Then, several improved key algorithms and experiments were studied. Finally, using the D-InSAR, PS-DInSAR and SBAS techniques, the subsidence of two experimental areas of Tianjin city and a coal mine, were obtained. The main research work and results in this dissertation are as follows:(1) The research statuses of InSAR technique were summarized. The insufficiency of InSAR and its related techniques studies were pointed out. The basic principles of SAR, InSAR and D-InSAR were described, and the application limitations of D-InSAR were analyzed.(2) A baseline estimation method based on the combination of precise orbits, the FFT (Fast Fourier Transform) and the ground control points was studied. A further research on the influence of estimation errors caused by the squint angle was analyzed. By comparing and analyzing the interferogram and sample altitudes, the correction and feasibility of the combination method are validated, and it can solve the problems of the single baseline estimation method to some extent.(3) An interferogram filtering method called considering the edge information based on DT-CWT was proposed, and its process flow was also designed. In the multiscale geometry transforming domain of DT-CWT, the edge coefficients were conformed by analyzing the transitivity of interscale coefficients and the correlation of intrascale coefficients. The edge and non-edge coefficients in DT-CWT domain were shrunk with different thresholds by the Bayes shrinkage function or the Bayes bivariate shrinkage function. The experimental results show that, this method restrains the interferogram noise stronger, and keeps the edges and details information of interferogram much better.(4) A new phase unwrapping method based on the hybrid particle swarm optimization algorithm (H-PSO) was proposed, and the least square phase unwrapping method was improved. By comparing with ten kinds of classical phase unwrapping methods, the correction of the methods studied in this dissertation is validated.(5) A relation model among confined water levels, exploitation quantity of groundwater, and the subsidence rate obtained by D-InSAR was established, and the experimental research on mining subsidence was also studied. In the experiment, the subsidence obtained by D-InSAR was smaller than the measured value. In order to solve this problem to some extent, two analysis methods for mining subsidence, such as the correction using control points and the multi-look process, were researched.(6) A method for selecting the master image called optimized coherence based on tangent function, and a double threshold algorithm based on the SNR of amplitude and phase for identifying PSC were proposed. Both of the two algorithms can be used as a supplement to existing methods.(7) The land subsidence of Tianjin city during 1992 and 1997 was obtained by PS-DInSAR and SBAS. 18906 and 42041 PS points were identified respectively by PS-DInSAR and SBAS. While, 16.4mm/a and 24.2mm/a of the maximal subsidence rate were obtained respectively by these two methods. Meanwhile, the subsidence during 1992 and 1997of a certain coal mine was calculated by SBAS method, and 380 PS points and 45mm/a of the maximal subsidence rate were obtained.更多还原