Study On Surface Deformation Monitoring Using Time-series High Resolution COSMO-SkyMed Images

There are some limitations in the application of long time-series surface deformation monitoring for traditional DInSAR technology because of spatial-temporal de-correlation and atmospheric artifacts. Currently, the rapid development of long time-series deformation monitoring means based on high-coherent point target provides a good idea for addressing the problem of spatial-temporal de-correlation and atmospheric artifacts. This paper extracts the surface deformation filed of experimental area based on small baseline set algorithm and evaluates the relative accuracy. Since the COSMO-SkyMed radar data has shorter wavelength, higher resolution, it will face more serious spatial-temporal de-correlation except for orbit errors, external DEM error and atmospheric delay error, meanwhile the city's high-rise buildings DEM error and atmospheric artifacts are also more serious. In response to these issues and COSMO-SkyMed images'unique characteristics, this paper studies some key technologies of surface deformation monitoring. The main contents are as follows:(1) Present the basic principles and data processing of InSAR, DInSAR in detail. Summarize the research status of long time-series high coherent point target DInSAR technology at home and abroad. Analyze the algorithm and principle of long time-series DInSAR technology based on high coherent point target in recent years.(2) Discuss the impact of final deformation measurement accuracy caused by orbital error. Get ground control points plane positioning error using direct geographical positioning technology based on the orbital parameters. Assess the COSMO-SkyMed orbital accuracy through plane positioning error indirectly.(3) Make a deep study of spectrum filtering algorithm, baseline estimation algorithm against some problems encountered in the data process of DInSAR. This improves operational efficiency and the accuracy of the final results, and provides a basis support for follow-up process to obtain high accuracy DEM and surface deformation field.(4) Get the average deformation rate figure and the cumulative deformation figure using SBAS-DInSAR method with COSMO-SkyMed image. Through the comparative analysis of the cumulative amounts of deformation with measured level point data obtained in the corresponding period, verify the accuracy and reliability of the monitoring algorithm.