Study On Surface Deformation Characteristics Of Wenchuan Earthquake Based On ALOS Satellite Data

Wenchuan area broke out Mw7.9 strong earthquake on May 12,2008.The main fault zone of the earthquake has been extended to the vicinity of the northern side of the Suhe River in Qingchuan County.In this earthquake,this paper attempts to study the surface deformation characteristics in two stages.coseismic and post-earthquake.The geostationary deformation field of Wenchuan earthquake is constructed by using advanced geodetic techniques such as D-InSAR and SBAS,and the law of fault migration is explored,and the monitoring of surface deformation in large area is carried out after the earthquake.Details as follows:1.The basic principles and data processing flow of InSAR,D-InSAR,SBAS-InSAR and data processing are described in detail.The error term(atmospheric error,orbit error)is weakened,The advantages and disadvantages of adaptive filtering,Boxcar filtering and Goldstein filtering in this seismic data processing are compared,At the same time,it shows the importance of the appropriate window and filtering times to thefiltering effect.2.The 6-track 60-scene PALSAR L-band data was tracked and MSP pre-processing before interference,The splicing and correction were performed again based on the nearest neighbor method,Based on the LOS projection value,the reliability of the InSAR observation based on the far and near field is evaluated by the 38 continuous GPS stations and 435 mobile GPS observatories published by China Crustal Movement Observation Network.The reliability of InSAR observations is evaluated based on far and near fields,contours,and hatching.A total of 11 PALSAR images were selected for the study of the deformation of An(county)Mau(county)area after the earthquake.The time series and average deformation rate were obtained by SBAS-InSAR technique.as the center of Shiguxiang area and boiling water town,analysis the relationship between the deformation and precipitation.3.The results show that the tectonic deformation field covers 83194 km 2 on both sides of the Longmenshan fault zone,and the deformation gradient near the fault is large,with the segmentation and thrust.Stripes along the fault was around the distribution,the overall northwest dish uplift,southeast plate down.The macro epicenter is 31.05 ° N,103.3 0 ° E in this monitoring.The near field ?0 is 16.9 cm and the far field ?0 is 4.5 cm.After the earthquake in the southwest of Anmao area was uplift,Uplift rate was15-30 mm / y,northeast and southwest sinking trend is obvious,the settlement rate was 20-45 mm / y.In June and July deformation rate accelerated,has a certain relationship with the local precipitation.Overall,It has a certain consistency and trend with the with the characteristics of the earthquake.