| Remote sensing technique is the important means of acquiring space information of the earth, active way of microwave radar sensing technology plays an important role in specific areas, due to the limits of application of optical remote sensing. Combining the principle of imaging SAR and interferometric technique, synthetic aperture radar interferometric technique is the extension and development of functions of general SAR, and it not only largely expands the function and application range of imaging radar, but also is of significance in both military and the development of national economy. InSAR can accurately measure three-dimensional arrangement of the ground point and its slight changes. At present, it has widely drawn the attention of researchers in areas of geomatics and earth science. Since1980s, the slow changes in ground subsidence have done great damages to the ground and buildings in different periods in Harbin, but no full-scale and systematic monitoring work has been done to the deformation of the earth’s surface. So, based on differential interfrometry of synthetic aperture radar, the thesis gets the information for the spatio-temporal change pattern of ground subsidence of recent years in Harbin.The thesis does a series research by means of conventional DInSAR, Small baseline subset and Permanent scatter method separately, based on processing the data of ERS and Envisat SAR in Harbin.Combined the monitoring data of water level with the data of level monitoring, and analyzing the related result of InSAR, the thesis proves its accuracy and reliability, which shows that the technique is efficient and feasible in monitoring the tiny and slow deformation in Harbin.The thesis analyzes the related basic concept of InSAR deeply, and raises a exploring and rejecting method for gross error while matching SAR Images. It also compares the filtering result of Interfereometric phase in space and frequency domain, discusses the correction methods of InSAR atmosphere effect, researches atmospheric delay correction based on MODIS data, and at the same time it develops the management system of the land subsidence monitoring network data based on GIS technique.Innovation achievement of the paper is as follow: 1. This paper is the first time to do a research on the situation of ground subsidence in Harbin completely and systematically by InSAR and gets the annual amount of settlement and accurates it to mm.2. In order to analyze the effect that the atmosphere has on the result of the interferometry, the author chooses the SAR image taken in Janu.1st and March30th,2006as the data source to proceed interferometric treatment, and MODIS data of March30th2006to correct the atmospheric delays. The result shows standard deviation has changed from0.8to0.65centimeters, which means MODIS amendment has certain effect.3. The thesis comes up with the variance components estimates for the whole inspection and Baarda single gross error detection method by analyzing and studying gross error in SAR Image registration and verifies it by actual example.Finally,46control points were used befor rejecting gross error points,and only32points were calculated in fitting polynomial coefficients.The result shows that deleting rate is up to30%.4. Because it is a result of analyzing the geologic structure, geomorphology and groundwater type in Harbin, and so detecting information of land subsidence is scientific and rational.It has more convincing,and provides the important reference of ground subsidence prevention.5. The thesis builds a monitoring network system of the ground subsidence,and the aim is more efficient management for the various images and data established by RS and GIS techniques. |
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