| With the continuous increase of ground subsidence,large-scale surface deformation monitoring has become a development trend.In recent years,due to the continuous increase of coal and deep groundwater extraction in the Luxi area,the range of surface deformation in this area has also expanded year by year Through the use of PS-InSAR technology for large-scale surface deformation monitoring in the Luxi area,when a large area of surface deformation monitoring is carried out,due to a single strip or limited track coverage,it cannot meet the research needs.The track monitoring results are spliced.This paper studies the key technologies of applying PS-InSAR technology in large-scale surface deformation monitoring.The main research contents are as follows:(1)By analyzing the changes in time,space baseline and Doppler centroid frequency during image interference,a comprehensive baseline and minimum method are used to optimize the selection of the common main image;at the same time,the PS point is initially selected by setting the amplitude dispersion index threshold,and then The integrated phase analysis method is used to optimize the selection of PS points,thereby improving the data processing quality of PS-InSAR technology.(2)Use the overlapping area between the strips of the same track to obtain the deformation information of the PS points with the same name,and use the weight distribution method to unify the benchmarks between the strips to realize the long strip data splicing,and cover the Shandong from July 2015 to March 2018 The three-band radar data in the central region was used to monitor the surface deformation,and the accuracy of the experimental results was verified by combining the observation data of the SDCORS station.The experimental results showed that there were two subsidence areas and two uplift areas in the study area,and the surface deformation in other areas was relatively stable.The maximum settlement is-266 mm,and the maximum lift is 83 mm.The correlation coefficient between the monitoring results of the strip data splicing and the points with the same name in the observations of the SDCORS station is 0.86,and the error in the deformation variable is 9.49 mm,which effectively realizes the data splicing of the results of the strip analysis of the same track.(3)By orthorectifying the SAR data,the ground coordinate system is unified,and the overlapping areas are processed based on the inverse distance weighting method and the robust least squares fitting method.The reference datum is unified,and the adjacent track data is spliced.And the surface deformation monitoring was carried out by using the lifting rail data covering the northern area of Shandong from January 2018 to July 2019 to carry out internal mutual inspection of the lifting rail calculation results and verification of the adjacent rail data splicing.The experimental results show: lifting rail calculation The results showed that the internal cross-check correlation was above 0.8,and the root mean square error of adjacent tracks was merged by robust least squares fitting method,which was 3.4mm,and the adjacent track data was accurately spliced.(4)Using large-area PS-InSAR solution result data splicing technology,selecting July 2015 to March 2018 elevation rail radar data to realize surface deformation monitoring in Luxi area,and analyzing the deformation results,it is found that there is obvious settlement in Luxi area There are 54 deformation zones,and the maximum value of cumulative settlement is-351 mm in the middle of Yuncheng County.At the same time,the accuracy of the solution result is verified by the observation data of SDCORS station.The result shows that the error in the calculation is 9.74 mm,the correlation coefficient is 0.93,and the deformation monitoring result has high reliability. |
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