Research Targeting Algorithm Based On Dual-mode Navigation Technology

The Global Navigation Satellite System(GNSS)is a system that uses the radio signals transmitted by space navigation satellites to locate and navigate user terminals.It has great significance for national security,precision guidance,geodesy,atmospheric prediction,and disaster prevention early warning.Among the many navigation systems,American global positioning system(GPS)is the most widely used,which has the characteristics of high precision,wide coverage and stable operation.For the sake of national security and social development,China has independently developed the Beidou Satellite Navigation System(BDS)to provide all-weather high-precision navigation,positioning and timing services for users around the world.With the rapid development of navigation in various countries,competition and cooperation in the field of navigation will deepen,and multi-mode integrated navigation has become one of the research hotspots in the navigation field.This paper proposes a positioning scheme for Beidou and GPS combination for the limited positioning efficiency and positioning accuracy in single GPS mode.This scheme has a wide range of positioning scenarios and more accurate positioning results.Firstly,by comparing and analyzing the feasibility of interoperability between Beidou and GPS system,the calculation method of satellite coordinates is given,and the source of measurement error is summarized.Secondly,the beidou and GPS satellite signals are captured and tracked,and the results of navigation message analysis are obtained.Finally using the method of pseudorange fusion calculation of beidou and GPS pseudorange equation.and users' 3d coordinates are obtained by using least square method and extended kalman filter algorithm.The paper uses the GPS-L1 and B1 I IF signals collected and stored by the RF front-end to analyze the scheme on the MATLAB platform.GDOP by comparative analysis of the least squares method and the three-dimensional extended Kalman filter results,The results showed that a combination of GPS positioning mode and Beidou proposed system with respect to a single GPS positioning mode and the positioning accuracy in positioning efficiency improved.