Research On Accurate Positioning Method Of Beidou Satellite Navigation System

With the development of Beidou system navigation and positioning technology and its application in various industries,its requirements for positioning accuracy are getting higher and higher.Therefore,how to improve positioning accuracy has become a hot spot for scholars and engineers.As a basic positioning method,pseudo-range positioning plays an important role in civil navigation and high-precision positioning initial position determination.As one of the main factors affecting the positioning accuracy,the multipath effect is not easy to weaken and seriously affects the positioning accuracy in densely-built urban areas.Therefore,for the two aspects of pseudorange positioning and multipath error,the main research contents of this dissertation are as follows:(1)Analyzed the data preparation in the early stage of navigation and positioning,including the composition and application of Beidou system,Beidou time system and coordinate system,analysis of Beidou receiver observation files and navigation messages,and weakening of errors in the signal transmission process.In addition,the basic algorithm Kalman filter used in this paper is compared and analyzed.(2)An improved algorithm model is proposed to solve pseudorange positioning.The model uses the characteristics of fast convergence of the weighted least squares method and high accuracy of Kalman filtering.On this basis,the Kalman movement is added to the window to ensure the accuracy of the positioning process and global convergence.The comparison of experimental simulation shows the effectiveness of the algorithm,which can improve the positioning accuracy and meet certain positioning requirements.(3)Aiming at the problem that the multi-path error seriously affects the positioning result during the positioning process,a model to suppress the multi-path error is proposed.That is,the first-order AR model is used to improve the colored noise,and the improved adaptive unscented Kalman filter is combined to improve the positioning accuracy.At the same time,a hardware platform composed of STC89C52 SCM,receiver antenna and ATGM332 D is built to verify the feasibility of the algorithm.