GPS Real-time Relative Positioning And Its Application In Earthquake Early Warning

As one of the modern geodetic technologies, precise crustal deformationduring the earthquake information can be obtained. In particular we canobtain instantaneous coseismic crustal deformation and even seismic wavesignal by use of high-rate GPS data which will provide us with a new datasource for further study of earthquake rupture process, seismic potterand earthquake inversion problem.We usually make precise GPS data processing by means of post-processingwith RINEX files. While post-processing can provide high-precisionpositioning results, it is weak in time-delaying, low temporal resolution,and other shortcomings.1) IGS final ephemeris solution operator canguarantee a high degree of accuracy, but we have to wait12days untilit is in public access; Even though we can use the IGS ultra-rapidephemeris, we need to fetch sufficient number of observations to form aRINEX file to solve.2) Post-processing software usually read in allobservational data at one time, so the computer’s performance willrestrict the amount of data processed, such as post-processing dynamicmodules in the Bernese and GAMIT, they can only handle about3hoursdata.3)Most of the conventional processing software can only handle upto1Hz sampling rate data, which are weak in capturing high-frequencydisplacement signal. Hence post-processing methods cannot meet therequirements of real-time, high time resolution of early warning forearthquakes and other natural disasters.In this thesis, I have made investigations as bellow:1) Basic theory of GPS relative positioning, including the time andcoordinate system, the observation model and parameter estimationmethod, and analyzed various errors the relative positioning can beaffected; 2) The principle of real-time relative positioning with trackRT isdiscussed, real-time processing of continuous station data is made,and its RIENX analog version trackRtr is tested;3) Mathematical model of extracting seismic wave signal from GPSpositioning results is invested. And I also study the method todetermine epicenter from trackRT results.