Comparative Analysis Of Urban Surface Subsidence Based On IPTA And SBAS-InSAR

The synthetic aperture radar interferometry technology has the characteristics of all-day,all-weather and high precision.It makes up for the shortcomings of leveling and GPS measurement and gradually becomes an important technical means for surface deformation monitoring.However,the development of D-insar technology is restricted due to the effects of spatiotemporal incoherence and atmospheric delay effect.On this basis,the PS-InSAR technology,SBAS-InSAR technology and IPTA technology can all solve this problem well,and have been successfully applied to surface deformation monitoring and so on.Interferimic Point Target Analysis(IPTA)and short baseline InSAR(SBAS-InSAR)technology were applied in this article,GAMMA software,ENVI SARscape software platform and Sentinel-1A SAR data in Liaocheng area were used to study and analyze the ground subsidence in a short time,and two types of variable rate model based on two kinds of technology were obtained.The accuracy and reliability of the two technologies were verified,and some valuable conclusions were obtained.The main results are as follows.(1)In IPTA technology,the selection of interferometric points is the precondition for the subsequent interferometric processing.Firstly the paper introduced the common interference method of point target selection,and then introduced the use of a single SLC spectrum in IPTA properties and use of the stable backscatter intensity intervention point target selection,the two methods and two kinds of methods to extract the final candidate.(2)On the basis of the sentinel-1a SAR image data obtained from Liaocheng Chiping in 2015.11-2016.8,the time series surface deformation rate model of the study area was obtained by using IPTA and SBAS technology respectively.The characteristics of surface deformation in Liaocheng are very obvious.Ground subsidence area was concentrated in Chiping,Dong’e and Yanggu.Among them,Chiping county was the most serious settlement,thus forming the settlement funnel area centered in chiping county.At the same time,it could be found that there was a certain level of ground rebound in the downtown area of Liaocheng.Using IPTA technology,the maximum land surface subsidence of Chiping county is 118mm,and the maximum accumulative subsidence rate of Chiping County reaches 121mm by using SBAS technology.(3)The surface deformation rate of IPTA and SB AS were analyzed comprehensively,and the results showed that the deformation rate trend obtained by the two methods was generally consistent,and the results were relatively reliable.