| GPS is a satellite navigation and positioning system aiming at the military needs, developed by America National Aeronautics and Space Administration in 1970's. Since GPS techniques were born, it has so many widespread and far-reaching applications such as on geodesy, geophysics, engineering, cadastre, digital Earth and environment monitoring and so forth. It has become one of the most important tools and means in these fields. Because the applications of GPS are very wide and these applications are interrelated, this author has made efforts to carry out a comprehensive and deep study of the application of GPS on geophysics. It will be useful to establish a basis for further study on the applications of GPS and space techniques to geophysics and other fields. The applications of GPS on geophysics include the realization of reference frame and the study of plate motion, the detection of crustal horizontal deformation and strain characteristics by GPS, the study of crustal vertical motion by GPS, the ionosphere activities monitored by GPS and GPS meteorology. In addition, GPS monitoring of the geocentric motion, Earth Orientation Parameters (EOP) and tides are also the content of GPS applications on geophysics. The geophysics information reflected by them is also very rich and important. The application of GPS on geophysics is very different from the traditional means of geophysics study. In many fields, the near real-time and wide area detection are done by GPS. It could be regarded as a revolution in detection means of geophysics. Both GPS based means and the traditional means of geophysics studies, such as earthquakes monitoring, geological detection and so on, reflect the activities and motions of individual terrestrial sphere from different viewpoints and different scales. Only when this information is fully combined, can the Earth in motion be well studied.The author studies the GPS applications on geophysics from the scientific viewpoints. At first, elementary theory of GPS measurement and GPS applications on geophysics at home and abroad are introduced. Then, the models and methods ofGPS data processing are studied in detail. It will be beneficial to obtain high accuracy and reliable GPS results. The preliminary standard for GPS data processing is drafted. Based on these studies, the methods of carrying out and establishing the terrestrial reference frame from space techniques are studied, and also the absolute plate motion model and relative motion model are studied and established. In addition, using recent 10-year GPS measurement data from some nationwide GPS networks, several regional GPS monitoring networks and the Asia-Pacific Regional Geodetic Project (APRGP), the crustal deformation in China and Asia-Pacific Region is studied in this thesis. Based on present-day plate motion model ITRF97VEL, a deformation velocity field of more than 260 sites in the three kinds of GPS networks is presented. From these results, we can see the crustal motion is evidently inhomogeneous. The crustal deformation in west China is far stronger and more complicated than that in east China, with the N-S seismic belt in China as a boundary. The displacement velocity gradually reduces from south to north and it shows shortening in north-south direction and extending in west-east direction due to the strong pushing of the Indian plate. The shortening of about 15 mm/yr and 9-13 mm/yr is accommodated across the Himalayan block and the west Tian Shan respectively. Within southern Tibet, between the longitudes 80?E and 91, there is E-W extension of 20.2 ?1.2 mm/yr. The slip rates of KJFZ in south Tibet and Altyn Tagh fault are 2-3 mm/yr and 4-6 mm/yr respectively. Our GPS results indicate there is a less than 7 mm/yr shortening across the Longmen Shan fault. These results support the supposition of crustal thickening. Along the Altyn Tagh fault to the Himalayan block, there is a NNE dispersive belt which is the boundary line of westward and eastward motions. East China is dominated by strike-slip motion and North...
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