Algorithm And Software Realization Of Vehicle Dynamic Positioning Based On GPS And BDS

Since the 1960s,the United States built GPS,GNSS has developed rapidly,which makes GPS,Glonass,BDS,Galileo becoming the representative of the multi-system common situation.Beidou satellite navigation system,independently researched and developed by China,has been covered by the Asia-Pacific.and BDS has gradually applied in the national defense information construction,national geography and national-conditions investigation,engineering survey,intelligent transportation and other fields,which is still in the stage of development.Phase-smooth pseudorange differential positioning has many advantages,and plays an irreplaceable role in both on-board navigation and traffic monitoring.And the way of using both GPS and BDS can solve the problem of fragile positioning enveronment when uses a single GPS,ensure the accuracy and stability of navigation and positioning.The main research work of this paper includes the following three parts:Firstly,According to the differences of GPS and BDS in time system and coordinate system,The author studies the multiple system integration theorySecondly,Several mathematical models including pseudorange single point positioning,pseudorange difference position and phase smoothed pseudorange differential position are established and analyzed.In addition errors are analyzed.Thirdly,Some important problems in phase smoothed pseudorange differential position are studied and realized,such as cycle slips detection,Smoothing window selection and the problem of determining the weight matric.Finally,The auther developed a software for post pseudorange differential positioning based on the algorithm in this paper using C++ and some experiments are designed to validate the algorithm and program.In this paper,the auther takes GPS/BDS in vehical navigation as an exemple.Compared the accuracy of GPS,BDS and the combined system in the way of pseudorange single point positioning,pseudorange difference position and phase smoothed pseudorange differential position.This paper draws that the accuracy of DGNSS is better than single point positioning,When the baseline length of Phased smoothed pseudorange with in 60 km,the precision of GPS/BDS is better than single system,the precision of P code with phase smoothed is better than C/A code with phase smoothed.Dual system phase smoothing pseudo range differential dynamic positioning accuracy can meet the 0.74 meter,when the observation conditions are good.