On the basis of Space-Wise Least Square method,three numerical methods including Cholesky decomposition,pre-conditioned conjugate gradient and Open Multi-Processing parallel algorithm are applied into the determination of gravity field with satellite gravity gradiometry data.The results show that,Cholesky decomposition method has been unable to meet the requirements of computation efficiency when the computer hardware is limited.Pre-conditioned conjugate gradient method can improve the computation efficiency of huge matrix inversion,but it also brings a certain loss of precision.The application of Open Multi-Processing parallel algorithm could achieve a good compromise between accuracy and computation efficiency.
High-precision data processing theories and methods for the wide area GPS network–––Asia Pacific Regional Geodesy Project (APRGP), are systematically discussed in this article. With the software bernese5.0 update, the annual results of APRGP coordinate, velocity field and the trend of plate movement are reestimated, and the corresponding accuracy of adjustment with different constraints, also the velocity field of APRGP, are presented and analyzed. Conclusions could be drawn that Eurasian plate (EURA) rotates clockwise, the Australian plate (AUST) and the Indian plate (INDI) move from southwest to northeast, while the Pacific plate (PCFC) is drifting to northwest, which shows agreement with those of IGS results.
CHENG PengFei , WANG Hua, CHENG YingYan, WEN HanJiang & CAI YanHui Chinese Academy of Surveying and Mapping, Beijing 100039, China
