GROUND DEFORMATION MONITORING AND ANALYSIS OF ZHONGCHUAN INTERNATIONAL AIRPORT BASED ON THE TIME SERIES INSAR OF SENTINEL-1A WITH ASCENDING AND DESCENDING ORBITS

Monitoring the deformation of infrastructure reliably is essential for assessing its structural health. This paper is based on 46 scene ascending orbit and 45 scene descending orbit Sentinel-1A radar images,and obtains the surface deformation rate and time series displacement of Zhongchuan International Airport from March 27,2017 to March 23,2020 and March 20,2017 to March 28,2020 using SBASInSAR and PSInSAR techniques at the same time. Four kinds of monitoring results are evaluated by means of internal and external inspection. Combined with the mean value of coherence coefficient,histogram statistics,deformation rate variance and its standard deviation,the most ideal deformation result is selected to analyze the causes of land deformation at Zhongchuan International Airport from human and natural factors. The results show that the deformation results of the four kinds of data are generally consistent. The variance and standard deviation of monitoring points from different orbit mode data are similar when the same time series InSAR technique is adopted. The deformation results of the same orbit mode data are slightly different when different time series InSAR techniques are used. The monitoring result of SBASInSAR is more robust than that of PSInSAR. Among the scattered subsidence areas in Zhongchuan International Airport,the deformation in the southwest corner is the most significant,and the maximum vertical subsidence rate of it can reach 11 mm·a^-1. The ground deformation of Zhongchuan International Airport is related to human factors such as road network and internal expansion. The stratigraphic boundary is not directly related to the internal deformation of the airport,and the land subsidence area is closely related to lithology. While further promoting the construction of Zhongchuan International Airport,the negative impact of excessive human activities should be avoided. The research results are expected to provide guidance and relevant information for land use planning and disaster prevention and control of Zhongchuan International Airport.