Application Research On Combined Processing Of Multi-source Data In Earth Surface Deformation Monitoring

The high precision surface deformation is the necessary informationfor seismic seismogenic mechanism research.GPS and Leveling,serving as excellent techniques in space geodesy,have good application effect on detecting horizontal and vertical surface deformation.However,the density of the GPS and Leveling observation is limited because of the high cost of the station construction and observation.The spatial distribution of the observationis more diffuse especially in mountainous and other difficult areas.In harsh areas,the observation density can not be guaranteed,and the difficulty of observation will surge.The application of DIn SAR and PS-InSAR techniques makes it possible to detect surface deformation with large area and high spatial resolution.But the deformation obtained by InSAR is the projection of the deformation in each directions in the direction of the radar's line of sight(LOS direction).It can not truly reflect the surface deformation.The combination ofthe result obtained by GPS,Leveling,and In SAR can make up for the drawbacks of a single means to get more reliable surface three dimensions deformation field.In this paper,the key earthquake area(tectonic area)southweat Tianshan is selected as the experimental area,and the GPS,Leveling and PS-InSAR observation data of this area in the same period or near period are collected.The deformation fields of the study area are obtained by the three techniques respectively.In this process,theadjustment of levelling network is constrained by the vertical deformation rate obtainedby GPS continuous station to reduce the influence of the datum point selection and the long-range observation error accumulation.Then,using the horizontal deformation rate obtained by GPS and the vertical rate obtained by leveling,the InSAR LOS deformation rate is adjusted and constraint processed to derive the high spatial resolution three dimensions deformation rate filed.The results show that the horizontal deformation direction of the southwest Tianshan area is northwest.The horizontal deformation rate is about-2~3mm / yr.The vertical deformation result shows the folds of the mountains is uplifting and the valley is descending,and the vertical deformation rate is-3~2mm / yr.This result is consistent with the existing research results of many scholars.The accuracy of the result has also analyzed with GPS and leveling result.It prove that the joint processing method for the GPS,leveling and InSAR observations applied in this research is feasible and reliable.The characteristics of the deformation distribution obtained in this research are related to the spatial distribution of the geological structure in this region,which has a certain demonstration effect on the inferring of geological structure,plate movement trend and stress at long time in this region.