Research And Implementation Of GNSS Carrier Phase Relative Positioning Algorithm

In recent years,GNSS positioning has been successfully used in various high-precision applications,and China 's Beidou third-generation satellite navigation system has launched navigation positioning and timing services to the world.With the progress of the society,people have become more and more strict about the positioning accuracy of GNSS in the fields of deformation monitoring and disaster warning.However,the original carrier phase observation in GNSS high-precision relative positioning has a cycle slip phenomenon,which makes it difficult to fix the ambiguity,thereby affecting the accuracy of GNSS relative positioning.In view of this,correct preprocessing of the carrier phase data is beneficial to improveing the accuracy of the GNSS relative positioning algorithm.The main research contents and innovations of this article include the following parts:1.The GNSS navigation and positioning method has been studied theoretically studied,the GNSS space-time reference frame,data format,and signal format have been analyzed,The analysis models of Positioning accuracy such as accuracy factor and station center coordinate system have been given.The least squares adjustment method and Kalman smoother filter algorithm have been used to solve and optimize the positioning data.According to the advantages of the Kalman filter algorithm,the accuracy of GNSS relative positioning has been improved.According to the actual needs,an interactive software based to Matlab guide integrated development environment has been developed.2.The theoretic research on the gross error detection method of GNSS navigation data has been carried out.An improved gross error detection method has been proposed for singlefrequency cycle slip detection.Its core is to use another weight function instead of traditional variance to weight carrier phase data.Simulation experiments have been performed on the Matlab platform with measured data.The results show that the reliability and effectiveness of the positioning data can be greatly improved.3.To deal with the problem of multi-frequency cycle slip,triple-frequency geometric-free equations have been established for the dual-frequency and triple-frequency observations.Aiming at the shortcomings of detecting the failure of special cycle slips,a new method of cycle-slip detection and repair has been proposed by combining simultaneous equations with Beidou(B1,B3)and(B2,B3)MW,which is also applicable in GPS.The conditions for determining the coefficient of the new geometric-free phase combination are derived,and(-1,0,1)is selected as the coefficient of the triple-frequency geometric-free combination.Experimental results show that this method can effectively detect and repair cycle slips.4.The traditional single-epoch ambiguity fixation method has been studied and analyzed in detail.The double-difference ambiguity resolution model has been used,and the concrete realization process of the fixed ambiguity drop correlation,discrete search,and RATIO value test has been studied.