Study On Earthquake Monitoring Technology Based On High-rate GNSS Observations

Since 20th century,the earthquake has been frequent in the world,the earthquake has caused the devastating destruction to the human homeland.It is very important to use effective means to monitor earthquake and make timely disaster warning.Because of the limited amplitude phenomenon in the seismic monitoring of traditional seismic observation means,the application of new observation means in earthquake monitoring becomes very urgent.With the advent of high-rate GNSS receivers,the layout of high-rate observation networks and the continuous updating of data processing software.Many scholars used high-rate GNSS observation data to calculate the coseismic displacement and surface deformation Caused by the earthquake.High-rate GNSS technology will become the traditional seismic monitoring means of effective supplement.Reliably record and analyze seismic activity.Based on the PPP?Precise points Positioning?and the dual-difference positioning technique,this paper systematically studies the high accuracy solution of high-rate GNSS data and the application of high-rate GNSS in seismic monitoring.Based on the high-rate GNSS data of IGS and the United States Plate Boundary Observation Network?PBO?and Shandong CORS.The PPP software MGP and the dual-difference positioning software GAMIT/GLOBK are used to process the high-rate data.Analyze the dynamic static positioning accuracy of the two positioning methods,and use two methods to obtain coseismic surface displacements during an earthquake.Firstly,the accuracy of two positioning methods is validated and analyzed,and the test results show that the the horizontal and vertical RMS values of PPP static and dynamic positioning are 3mm and 8mm respectively,and the RMS values in elevation direction are 1cm and 4.1cm.The double difference static position,the average baseline length is 2000km,the maximum coordinate deviation is less than 1.9cm,the relative precision reaches10^-9.The double difference dynamic localization,short baseline?d<100km?,positioning accuracy is about 2cm,long baseline?100km<d<500km?,positioning accuracy is about 2.5cm.Comparing the accuracy of the two positioning methods,when the baseline length is 700km,the accuracy of PPP and double-difference positioning is equivalent,and the RMS value is about 4.5cm.The program design stellar day filtering algorithm removes the unmodeled noise during the positioning process.The experiment verifies that this algorithm effectively weakens the satellite orbit and the observation station environment-related errors.Using the two localization methods,the high sampling rate data of the IGS station in the near-seismic area of the Japan3.11 earthquake and the CORS station of the far-seismic area were solved,and the coseismic displacement and the instantaneous coseismic deformation sequence were obtained.The IGS station in the near earthquake area has the maximum displacement of about 228.9cm,and the instantaneous deformation is about 3m;the CORS station in the far-seismic area has the coseismic displacement of about 1cm,and the instantaneous deformation is about 11cm.A series of tests prove that PPP and dual-difference positioning can accurately resolve high sampling rate GNSS data observed during an earthquake.High-rate GNSS is an effective technique for seismic monitoring.