Researches On BDS Triple Frequency Static Precise Point Positioning

Beidou satellite navigation system(BDS)is a global satellite navigation system,which is developed in China independently,and been provided positioning,navigation and timing(PNT)services in the Asia Pacific region.At present,BDS is in a high-speed development stage and is expected in 2020 to provide passive services for users worldwide.Precise point positioning(PPP)technology has been widely used in all walks of life because of its advantages of high positioning accuracy,low cost,convenient operation and so on.How to make full use of the superiority of the triple frequency signal system of BDS and the precise point positioning technology,and improve the positioning accuracy and reliability of BDS,has become a focus of research.This paper mainly focuses on the research of the triple frequency precise point positioning technology.The research contents can be summarized as follows:1)Theory research on precise point positioning technology.This paper introduced positioning observation equations and all kinds of errors influenced the positioning performance have been introduced,and illustrated the treatment strategies of these errors in precise point positioning;the typical mathematical model of precise point positioning;besides,it described the precise point positioning data preprocessing steps and two kinds of common parameters estimation method.2)An improved model of dual frequency precise point positioning is proposed.Using different strategies to deal with the satellite terminal deviation of carrier phase observations and pseudorange observations,so that the influence of the difference between the two kinds of observations on the positioning accuracy can be eliminated,and then the correctness and validity of the improved algorithm are verified by the measured data.3)The BDS triple frequency ionosphere free combination of real positioning model has been constructed,and the triple frequency precise point positioning performance has been preliminarily evaluated.This paper studies the triple frequency observations of combinatorial theory firstly,based on this,the triple frequency ionosphere free combination real location model is constructed,and then using the data measured,conducts the researches on the triple frequency and dual frequency BDS precise point positioning,and dual frequency GPS precise point positioning,which draws the following conclusions:the performance of three frequency and dual frequency precise point positioning of BDS are very stable and the differences of positioning accuracy are slightly.However,the positioning convergence time and positioning accuracy of the BDS triple frequency precise point positioning are better than that of dual frequency;the convergence speed and positioning accuracy of triple frequency BDS is poor than that of GPS dual frequency performance,but the positioning accuracy can also achieve the level of centimeter;with the future development of the BDS,and the improvement of the BDS precision products,the positioning accuracy and convergence speed of the BDS triple frequency precise point positioning will be further improved.