Researches On Unification And Data Processing For High-Precision GPS Networks

This dissertation systematically investigates the unification of high-precision GPS networks and the theory and methodology of its data processing. The following problems are discussed: GDReference datum and adjustment methods on the unification of high-precision GPS networks, tilization of the global IGS stations in unification, ormulations of the adjustment model on the high-precision GPS combined adjustment, @~Combinations between the local GPS networks and the crustal movement observation network of China, (~)Crustal movement and deformation between the different observation epochs, ã‚›nd Choice of systematical parameters on the combined adjustment. In detail, the main content of the dissertation includes:The design ideas of combined observations on the local 01 networks and the crustal movement observation network of China are presented. The technical design scheme of combined observations on the first order and second order 01 networks and the crustal movement observation network of China has been performed.Adjustment methodologies and their theoretical backgroud on the high precision GPS networks are systematically investigated. The implication of corresponding datum for various adjustment methods is analyzed. The transformation formulas based on different datum and different epochs are derived and formulated.The GPS data processing method based on Bayes theory is presented. Bayesian estimates of the model parameters as well as their posterior covariance estimation formulas are derived.The systematical investigates onhe choice of reference station in the high-precision GPS data processing, the coordinate constraint of reference station and the effect of incorrect weights to adjustment results are made. Some general principles on the choice of reference station and some effective methods on choosing weights in adjustment are presented.The adjustment model for combined GPS networks considering systematical parameters for the coordinates frames and parameters for the crustal movement is established. In terms of this model, parameters for the plate motion and for coordinates transformation can be separated. Therefore, the precision and reliability of parameters for coordinates transformation can be improved.In terms of the theory of strain analysis, the inner deformations of plates caused by the crustal movement are studied. The robust estimator for strain parameters as well as the influence function of observation errors to solutions is derived and formulated. The strain field of the crustal movement for China mainland is analyzed and discussed by the plentiful real GPS observation data.