Surface Deformation Monitoring Method Based On Sentinel Dual-polarization Data And Its Application In Coal Fire Monitoring

The assessment,prediction,and treatment of the natural environment of coal fire areas have attracted widespread attention in recent years.InSAR technology is an effective tool for large-scale monitoring and evaluation of coal fires.The use of InSAR technology to detect fire areas has become a research hotspot.In the actual application,using InSAR technology to monitor coal-fire often limited by the low-coherence natural environment,which leads difficult to obtain the coal-fire area subsidence.With the launch of polarized SAR satellites,it has become possible to use SAR data polarization information to solve the low coherence problems.To this end,this paper makes full use of the dual-polarization sentinel data to carry out the phase timing optimization in the deformation detection,and overcomes the influence of the low-coherence ground cover in coal-fire area when using InSAR to detect deformation.Moreover,this thesis realized the deformation detection of the small and complicated fire-area in Fukang,Xinjiang.The main research work and results of this article are as follows:(1)The basic principles of InSAR,D-InSAR and TSInSAR technology are explained in summary.Pointed out the basic characteristics of SAR imaging,the defects in the application of D-InSAR technology and the detection of distributed target deformation by time series InSAR.Finally,Describethe concept of polarization interference,introduced a polarization coherence optimization method under the condition of Single-Baseline.(2)The polarization timing optimization method based on the sentinel dualpolarization data is described in detail.In the phase polarization optimization of the multi-baseline TSInSAR,two polarization methods are introduced in detail for different types of scatterers.The polarization timing optimization of the permanent scatterer is under the dispersion criterion,and the polarization timing optimization of the distributed scatterer is under the coherence criterion.Finally,the calculation of the optimization quality evaluation index: phase standard deviation,is described.Experiments were conducted in the Pudong Airport area with abundant mechanisms,and the deformation monitoring capabilities of the polarization timing optimization method were discussed.(3)This thesis use Fukang fire area in Xinjiang as study area,carried out the surface deformation detection.Under the consistent standard,selecting high-quality monitoring pixels through the phase standard deviation,use PSI,SBAS,PolPSI and Pol SBAS(under the optimization of polarization timing sequence)completed the deformation detection of Fukang fire-area.The results show that the four monitoring results consists well,besides,the Pol SBAS method can obtain high-density points in the low-coherence small coal-fire area.More important,the final deformation results are in good agreement with the coal-fire points.