The Spherical Wavelet Representations Of Regional Gravity Field And GPS Velocity Field

The development of the satellite gravity measurement technology, which could provides abundant gravity observations, makes it possible to obtain the low and intermediate frequency information from the gravity field with high precision. Combining the airborne gravity with the ground gravity measurement, one could obtain the detail information for the regional gravity field. The change of natural environment and various geological events make the gravity field changing over time. The spherical waveletcan be localized both in space and frequency domain. It is meaningful to adopt this method to study the regional gravity field and GPS velocity field, and it is also the main topic of this thesis, the main work are as follows:1. The method of wavelet analysis and its research status in the gravitational field and other fields have been introduced.2. The method of wavelet modeling for the GPS velocity field and gravity field was provided. The scale selection and the regularization in the wavelet modelling are also studied.3. The GPS velocity observations in southwest China of the Crustal Movement Observation Network in China (CMONC) were used to establish velocity models by using difference of Gauss (DOG) spherical wavelet, and multi-scale analysis was conducted. The results show that the spherical wavelet analysis can effectively depict the large-scale characteristics and small-scale movement of the velocity field. The accuracy of the model is ±2.01 mm/year for EW direction, and ± 1.58mm/year for NS direction using external check.4. The large linear equations and the associated lack of computer memory problem were solved by using domain decomposition method and iteration method while modeling the regional gravity field by spherical wavelet. The 2.5'×2.5'grid gravity anomaly data from EGM2008 for study area (117°E?128°E, 13°N?26°N) was used to establish regional gravity field models by using difference of Gauss (DOG) spherical wavelet, and the mean square deviation between observations and model is ±4.01mGal. The low frequency and high frequency components of gravity anomaly are obtained by multi-scale analysis of gravity anomaly, and the tectonic information can be also obtained by further analysis.