Study On The Subsidence Monitoring In Renqiu Area With Time Series InSAR Technology

Land subsidence is a very common geological disasters phenomenon,it can do great danage to buildings and human beings,in order to reduce this hazard prevention brings life and economic losses,it is necessary to take long-term stable and reliable measurement to monitor deformation region. Due to the defects of high cost and non-continuous monitoring exist in monitoring subsidence in deformation areas by conventional measuring method, a method based on time series InSAR technique is proposed to monitor the deformation of Renqiu, which is funded by the public projects of national administration of surveying, mapping and geoinformation of China(ID:201412016).The main work is as follows:1)It highlights the geometric principles of rapid-way D-InSAR technology and composition of the interference phase result,and commonly data processing software of D-InSAR technique are introduced,analysis the D-InSAR data processing in detail. Finally, describe the D-InSAR technology limitations from time decorrelation, spatial decorrelation, atmosphere delay and over big deformation gradient and other factors caused decorrelation.2)Using PS and SBAS technology,respectively, to process the ASAR and PALSAR data of Renqiu area, get the maps of deformation rate distribution,and compare the results of PS and SBAS:The deformation's consistencies of space contribution and magnitude are quite well, according to the PS-InSAR technique results of the two data; and space contribution of SBAS results are quite well too, but the maximum annual deformation rate of PALSAR and ASAR data, were-31.8mm / yr and-35.4mm / yr respectively.There is a quite big difference in magnitude of PS and SBAS results, the coherence of PALSAR is much better than ASAR data, but due baseline of PALSAR is too long that its decorrelation phenomenon is more serious.3) Explore the D-InSAR and PS technology which can play a greater role in the detection of small deformation, compare the D-InSAR and PS monitoring results in the experimental area, the results showed that D-InSAR technology cannot detect obvious phenomenon, while PS technology can detect small deformation.4) In order to solve the problems of ASAR data's poor coherence and low PS dot density, adopt TCP technology to process the ASAR data, and compare the TCP results to PS results with filter, obtain the research area's maps of deformation rate distribution:TCP density selected by TCP technology is 133/km2, which is much higher than the PS dot density selected PS technology, thus TCP technology weakens sparse PS points of the ASAR data.The maximum deformation rate in interesting area of TCP results can be-18.4mm/yr, and PS reault with filter is-18.1mm/yr, there is a better consistency of PS and TCP results, it can explain TCP and NL filtering method is reliable in some degree.