Research And Application Of Key Technology Based On Precise Positioning Of Bei Dou Satellite System

The Bei Dou satellite navigation system,as an important space infrastructure in China,is a positioning and navigation system that is being implemented and operates independently.Bei Dou system not only can provide navigation and positioning services with all-weather,all-time,high-precision standards,it has also been successfully applied in many fields and its service objects and service areas are gradually extending.Because of this,the research on the technology of accurate positioning of Bei Dou satellite system is also very important.This thesis analyzes and discusses the positioning problems in Bei Dou high-precision positioning and the cycle slip related issues that need to be solved in the carrier phase data.The main research contents are as follows:Firstly,the receiver is initially positioned using pseudorange positioning technology,and combined with the Bei Dou pseudorange positioning principle,the research is carried out on the basis of the classic pseudorange positioning algorithm.Aiming at the problems of limited positioning accuracy and linear error of classical algorithms,this paper proposes an improved least squares method based on dynamic threshold based on the classical least squares method.Taking advantage of the fast convergence speed of the improved least square method,the iterative result is used as the initial state of the Kalman filter algorithm.The correction model of the improved Kalman filter algorithm is used to solve the position.Based on this,a hybrid positioning algorithm is proposed.The improved algorithm not only improves the positioning accuracy,but also has strong adaptability.Secondly,aiming at the problem of cycle slip during the positioning of Bei Dou system using carrier phase observation measurement,the traditional cycle slip detection method is verified for different types of cycle slip detection effects and performance,as well as the detection and repair capabilities at different sampling rates.Finally,based on the principle of traditional wavelet transform to detect cycle slip,this paper proposes a wavelet transform method based on improved cycle slip detection amount.First,the MW combination and geometry-independent combination are used to construct the cycle slip detection amount,then combined with the advantages of wavelet transform that it can observe the signal details and it can magnify the small cycle slip,and finally achieve the cycle slip detection process.The experimental results show that the improved method can have significant effects on cycle slip detection of less than 1 week.