Sentinel-1a Data Urban Deformation Monitoring Applicability Analysis And Missing Data Fitting Research

Surface deformation has the characteristics of susceptibility,slow change,cumulative and irreversible.Large-scale surface deformation will affect urban roads,bridges,underground pipeline facilities and above-ground structures,and serious surface deformation may even directly threaten life safety.In order to assess the impact of surface deformation on infrastructure such as urban structures,roads,and pipelines,the acquisition and analysis of surface deformation data is particularly important.Synthetic aperture radar(Synthentic Aperture Radar,SAR)is an active microwave sensor.Synthetic aperture radar interferometry has the advantages of non-contact,all-weather,long-distance monitoring,etc.,and can achieve continuous and highly automated monitoring of local areas.Although synthetic aperture radar interferometry has been widely used in disaster warning and settlement monitoring.However,the accuracy of synthetic aperture measurement results is also constrained by many factors,such as SAR data resolution 、 SAR data technology processing techniques 、 methods and atmospheric delay errors.At the same time,due to various decoherence phenomena,there will be a lack of ground deformation information obtained by synthetic aperture radar interferometry,which seriously affects the final deformation monitoring results.In response to the above problems,this article has made detailed experiments and research,the results are as follows:(1)The principle of InSAR(Interferometric Synthetic Aperture Rader)technology is introduced in detail,and the applicability of different data sources and different deformation fields to different SAR processing technologies is compared and analyzed.This paper uses 2017-2018 Beijing Sentinel-1A data as the source data,and for the relatively low resolution of Sentinel-1A data,the SBAS(Small Baseline Subset)method is selected to process the data to ensure the reliability of the interference phase,To obtain accurate InSAR deformation monitoring data of Beijing urban area.At the same time,combined with the existing precision level data,the accuracy and reliability of Sentinel-1A data as the source data for urban deformation monitoring were verified.(2)As an important monitoring method,InSAR synthetic aperture radar interferometric measurement technology has been more and more widely recognized for its application in surface deformation monitoring.Domestic scholars have also conducted a lot of experimental research on this.However,studies related to InSAR deformation monitoring have found that the InSAR data maintains a good correlation in autumn and winter,and the vigorous vegetation growth in spring and summer will cause the data to be uncorrelated.In view of the above problems,thisarticle uses experimental methods,combining InSAR measurement data and actual level data,and using experimental methods,fitting analysis,and correlation analysis methods to further verify the above views.At the same time,the three typical landforms of the constituency city: structures,green spaces,and roads were analyzed for the suitability of urban deformation monitoring based on Sentinel-1A data.The results show that: Sentinel-1A data can be well applied to the deformation monitoring of urban structures and road terrain,but there are obvious errors in the deformation monitoring results of green terrain.(3)In view of the problem of the lack of deformation information obtained by InSAR technology,this paper analyzes in detail the three methods of inverse distance weighted interpolation fitting method,moving trend surface analysis model method and Kriging interpolation model method in the deformation information fitting The applicability and reliability of the proposed Kriging interpolation model for estimating the variation function.The experimental results show that the accuracy of the moving trend surface analysis model method is relatively poor;the accuracy of the inverse distance weighted interpolation fitting method is better than that of the moving trend surface analysis model method;the Kriging interpolation model method with high accuracy is considered,which can be effective The fitting is based on the missing data of the deformation information of the urban area of Sentinel-1A data to ensure the integrity of the obtained data.