Study On Application Of Time Series InSAR Technique For Subsidence Monitoring Considering Scatterer Height

Land subsidence is a geological phenomenon in which the regional ground elevation is continuously reduced due to consolidation and comp-ression of the soil in the surface layer of the crust under the influence of natural and man-made conditions.It has a wide range of impact,long duration,complex causes,and difficulty in prevention and control.At present,it has become one of the most important geological disasters in the process of urbanization.In recent years,there have been many time series InSAR techniques in the study of subsidence monitoring.However,most of their researches are based on planes and do not perform detailed analysis of deformation information from a high level.Therefore,this paper introduces high-level information into it,taking into account the scatterer height time series InSAR technology settlement monitoring research,and apply it to Beijing-Tianjin high-speed railway settlement analysis.The main work is as follows:(1)The basic principles of InSAR and DInSAR technology are briefly introduced.The decoherence factors that affect the accuracy of DInSAR monitoring are analyzed.The algorithm principles and processing flow of the two mainstream time series InSAR technologies-PS-InSAR and SBAS InSAR are summarized and separately analyzed its advantages and disadvantages.(2)The building height extraction algorithm based on the statistical analysis of amplitude dispersion and interferometric phase information is mainly described and combined with the Multiple images Coherent Targets Small Baselines InSAR(MCTSB-InSAR)to extracted the building height and the inversion result of the deformation in the study area.At the same time,according to the height information,the properties of scatterers are distinguished,and the deformation information at different height levels is analyzed in detail.(3)Taking Beijing-Tianjin high-speed railway as an example,through high information to screen high coherent targets along the high-speed railway.The settlement information along the Beijing-Tianjin high-speed railway between the Tianjin section of 2009-2010 and the Beijing section of 2011-2016 was obtained.Spatially,correlation analysis was made on the average settlement rate,uneven settlement,slope change,etc.,with respect to the high-speed rail(longitudinal)and the vertical direction(lateral).The results showed that the Beijing-Tianjin high-speed railway in the study area is in safe operation within the corresponding time period.In terms of time,the relationship between precipitation and time series settlement of high railway time series is analyzed in tianjin section.The experimental analysis shows that there is a certain correlation between them.The accumulated time series of its spatial-temporal evolutionary process was plotted for the Beijing segment from 2011 to 2016,the maximum cumulative settlement along the Beijing-Tianjin High-speed Railway was up to-565mm.The study has certain reference significance for the operation and maintenance of the Beijing-Tianjin High Speed Rail.