The Method Research On High-Precision Baseline Solution Of BDS/GPS Combination

Beidou satellite navigation system has been officially offer regional services. In China and surrounding areas, the number of visible satellites on BDS/GPS joint positioning is close to 21, which can greatly improve the availability and reliability of GNSS navigation and positioning. The comprehensive utilization of BDS/GPS multi-frequency signal, also can improve the performance of the high precision measurement. Researching theory and algorithm of BDS/GPS integrated real-time precision positioning, not only is of great significance for real-time precise positioning service under the condition of multiple GNSS, but also benefits BDS industrialization promotion in the field of high precision measurement.In this paper, the BDS/GPS integrated precision positioning theory and algorithm was studied thoroughly, the BDS/GPS integrated baseline calculating method of single epoch and medium-long baselines integer ambiguity fixation function model was mainly researched,besides algorithm was authenticated and the data was analyzed using measured data. The main research content is as follows:1.Systematically introduced the basic theory of the GNSS observations linear combination, detailedly introduced Observation of double-frequency linear combination and three frequency combination and error analysis,and the GNSS positioning error sources and correction method.2.Investigating the BDS/GPS integrated baseline calculating method of single epoch, by solving the wide lane and narrow lane ambiguity to realize single L1 ambiguity, studying the carrier phase calculating model based on regularization and stochastic models of BDS/GPS integrated positioning.At last,using BDS/GPS integrated measurement data carried out experiment, the rate of single epoch short baseline integer ambiguity fixation reach to 100% and precision of the positioning accuracy approached to cm-level.3Introduced the principle of medium-long baseline calculation in detail.In the condition of fixing wide ambiguity,broke integer ambiguity of combination of free ionosphere into wide lane ambiguity and L1 ambiguity,besides fixed L1 ambiguity using LAMBDA algorithm.In the end,carried out an experiment making use of BDS/GPS integrated measurement data,during the process of this method, the fixed accuracy of integer ambiguity of wide lane is up to 100%,and L1 is over 98%,ultimately positioning results are less than 3 cm in E、N and U directions, which proved the reasonable and effectiveness of the algorithm in this actile.