Experiment Research On The High-pricision Baseline Processing Of Beidou

Beidou second-generation satllite navigation system(BDS)has the capability of positioning services in Asian-Pacific region,and a large number of continuously operating reference stations(CORS)of Beidou have been built in china and were put into operation in May 2016.In order to take advantage of BDS and ensure that CORS can provide accuracy coordinate reference service,high-precision baseline processing based on the data of BDS is critical.However,about the GNSS data processing,the current internationally recognized two high-precision solution software programs:Gamit version of 10.6 and Bernese version of 5.2 have integrated the codes of most of GNSS into themselves but are still unable to process the data of BDS.Therefore,the high-precision BDS data processing will be the focus of research.In this context,the theory of high-precision GNSS data processing is researched and the errors and influence factors in the process of data processing are analyzed by experiments with measured data.Finally,the software of high-precision data processing of BDS is developed in this dissertation.The main content and contributions of this dissertation are summarized as follows:1.By researching on the main errors:troposphere delay and antenna phase center correction,it is found that ninety percent of the bias of relative troposphere delay estimated by the model of GPT/GMF combining with the addition parameter method is better than 1cm compared with GPS.The influence of antenna phase center correction cannot be ignored for middle-long baseline and the impact can be up to 6mm.By researching on the three influence factors:cutoff angle of satellite,different weight for satellites on different orbits and algorithm of ambiguity resolution,the experimental results show that the suitable weights for Inclined GeosynchronousOrbit satellite(IGSO),Medium Earth Orbit satellite(MEO)and Geostationary Orbit satellite(GEO)respectively can improve the precision and repeatability of the BDS solution when data of BDS is processed.About algorithm of ambiguity resolution,SIGMA algorithm for short baseline and QIF algorithm for middle-long baseline are more suitable.2.Based on the software called Common GPS Office(CGO)that developed by SouthWest JiaoTong University,it has been developed to be equipped with the capability of high-precision data processing of BDS.And according to the conclusion of analysis of influence factors.the optimal parameters are selected in the process of baseline.Finally,the static data of Sichuan CORS of seven days are used in the experiments.The results that caculated by Bernese5.2 with data of GPS and upgraded CGO software with data of BDS are compared to verify the performance of the latter.About the solution of single baseline,the bias of baseline component is better than 7mm in the plane direction,and the bias is better than 26mm in the elevation direction.About the performance of network adjustment,the bias is better than 8mm in the plane direction,but the bias is larger in the direction and better than 18mm.