Research On PPP/INS Tightly Coupled Integration And Realization

The integrated navigation technology of Global Navigation Satellite Systems(GNSS)and Inertial Navigation System(INS)has become an important means for users to obtain high precision space position,speed and attitude information in the field of mobile measurement.Nowadays,DGNSS/INS integrated navigation technology combined with GNSS differential positioning and INS has been widely applied.However,PPP technology is an absolute positioning method without reference stations,no distance constraints and only a single GNSS receiver to obtain high precision position information.PPP/INS integrated navigation will be more suitable for large-scale mobile measurement work and has wider application prospects.This paper focuses on the research of PPP/INS integrated navigation system,realizes the PPP/INS compactly combined algorithm and uses high dynamic vehicle experiments to verify and evaluate the compact combination of PPP/INS.The main work of this paper is as follows:(1)The strapdown inertial navigation algorithm in the geocentric coordinate system is deeply studied,and a set of navigation equations in the self-consistent geocentric coordinate system is given,and the initial alignment method is carefully studied.(2)This paper makes a thorough research on the un-differential precision single point positioning technology,makes detailed comparison and analysis of several mathematical models of PPP,and expounds the error source processing model and parameter estimation method in PPP in detail,and realizes the PPP algorithm by programming.The positioning performance of PPP is analyzed by multi group IGS station observation data and measured high dynamic experimental data.The results show that the positioning precision of static PPP can reach centimeter to millimeter,and the dynamic positioning precision of the vehicle experiment in this group can reach decimeter to centimeter level positioning.And the accuracy of the PPP solution is equal to the commercial software IE8.60.(3)The difference between the two kinds of PPP/INS combined structures is analyzed systematically,and a compact PPP/INS combination model based on single difference is constructed,and the compact combination algorithm of PPP/INS is realized through program design.In the same way,the test and analysis of the tight combination performance of PPP/INS are carried out by the measured data of high dynamic test.The result shows that in the position precision,the tight combination of PPP/INS has a certain increase relative to the PPP,and the result is more smoother.At the same time,the compact combination of PPP/INS can also obtain the information of the carrier velocity and attitude with high precision,and it can meet the needs of the user.