Study On The Characteristics Of Crustal Movement And The Quality Of Geocentric Reference Frame In China

The definition, renewal and maintenance of geodetic datum have been international hot issues. In recent years, many countries and regions have been studying and implementing in modernization and renewal in local geodetic reference coordinate frame. Our country started CGCS 2000 on July 1st 2008, which was composed of CORS network and national high-precision geodetic control network. In order to estimate the precision, dynamic and reliability of geocentric coordinate framework, this paper is focused on definition, renewal and maintenance of geocentric coordinate framework. The analysis are based on the precise result of CORS and national GPS network, and two analysis methods are adopted: the first one is the crustal movement characteristics, and second one is the quality of coordinates and velocity. The main research works and results are as below.1. This paper studied the establishment methodology of ITRF and CGCS network, the ideas are referred which create unified space-time geodetic datum through the long-term reference frame and short-term reference frame, and the unique methods to obtain the dynamic, high-precision geocentric coordinate framework through the construction of CORS network are referred2. The data of recent 10 years continuous observation results from state CORS network and the data between 1999 and 2007 from the mainland GPS network have been finely processed, the coordinates and velocities of Chinese mainland are obtained, which is the most precise (coordination better than 5mm, velocity better than 2mm / a), Wide area (covering Chinese mainland), and densest (1081 points).3. Crustal movement velocity field and its gradient field are inferred through the GPS-derived velocity field data, and the model of crustal deformation velocity field for the Chinese mainland has been established base on the adoptions of Euler vector model and similar transformation methods, on which, the regional crustal deformation characters of china mainland have been further analyzed.4. This paper summarizes the principle used to choice frame stations of Chinese geocentric coordinate reference frame, and the further studying on stability and dynamical of frame stations have been implementing.5. The short-term frame is realized by the time series which are derived from weekly result of CORS, and the quality is analyzed based on the coordinate time series and coordinate components repeatability which abstained from weekly resolves.6. Multi-resolution is used to analyze the coordinate components repeatability, and the error characters of coordinate time series are investigated. Wavelet analysis and spectral method are implemented to analysis GPS time series in height component generated from CORS network, and indicates that the time series of CORS station has some periodicity, especially the periodicity in the elevation direction.