Research On Data Processing Of GPS For Crustal Deformation Monitoring

GPS technology is highly regarded by many countries because of its high precision and all-weather real-time observation and so on.As the growth of GPS tracking stations' s establishment,geoscience also improved GPS data processing software to improve its accuracy and applied observation data by GPS to all kinds of geoscience research work,such as earthquakes,volcanoes,ground fissures,tsunamis and other crust movement.After many years' continuous observation of the GPS site,it has accumulated a lot of data,which provides a wealth of data base for the regional crustal deformation analysis.This paper describes the development history and precision of the ITRF framework,compares the accuracy between the various frameworks,prepares the benchmarks for GPS data processing,and explores the effects of long and short baseline solutions and coordinate precision on different modes.At the same time,we use GPS continuous observation data from Southern California to obtain the GPS coordinate time series and the horizontal velocity field in the Southern California area.The main contents and progress of this paper are as follows:(1)This paper explores the impact of different frameworks on GPS sites.ITRF is constantly refined with time.It is necessary to unify the framework for different periods of data and the choice of framework plays an important role in benchmark for data calculation.(2)In this paper,the long and short baseline hybrid solutions are also explored.The long and short baselines are studied from the aspects of baseline solution strategy and baseline convergence.When the precision is high,the large area GPS hybrid network Can not be long and short baseline mixed solution but need separated network and solution.(3)In this paper,we use the data of Southern California to obtain the time series of the region and analyze and deal with it.We remove the trend items and carry out fast Fourier transform to obtain the annual and semiannual periods.It is found that there is an anomalous period signal deviating from 1.0cpy,which may be caused by common mode error,surface load and GPS unmodeled error.(4)In this paper,we use the data of Southern California to obtain the velocity field in the framework of ITRF2008.The overall velocity is 47.3 degrees northward.Using the Euler vector formula,we deduce the plate movement to obtain the speed of the North American plate and the situation of west of 41.7 degrees.The results provided with the unavco website and the Southern California Earthquake Center are basically the same in trend and magnitude and the results are reliable.