Satellite Simulator Navigation Message Of The Simulation Analysis And Verification

Today, the global navigation satellite system is in the development stage, With thegrowing demand for satellite navigation services, China has already researched in the firstgeneration of satellite navigation systems based on the research and development of theCOMPASS satellite navigation system. For the satellite navigation services, thecalculation accuracy of the satellite’s orbit and the accuracy of the navigation messagebroadcast ephemeris parameters are closely related. In this paper, the analysis andverification of the simulation of the satellite signal simulator navigation message.Firstly, Considering the models of perturbation forces including the earthnon-spherical effect, the lunar gravity and the solar gravity, and the solar radiationpressure, the equation of satellite motion in ECI (Earth Centered Inertial) coordinatesystem is established and extrapolated satellite orbital data.The result is that the model isadded, the positioning deviation is small.Secondly, the design of the broadcast ephemeris parameters algorithm to generate thecorresponding period of satellite orbit data, applied to the satellite signal simulator, theimport will generate satellite signal receiver for closed-loop test receiver positioningdeviation based on a least squares fitting in meters level. The test results verify thefeasibility of the ephemeris extrapolation method, so that the GPS satellite simulator longsimulation without continuing to read from an external ephemeris.Finally, the study L2CNAV message content analysis CNAV and NAV navigationmessage data content, coding performance, choreography structure, as well as broadcastway improvements CNAV broadcast ephemeris parameters change and the change of theparity bit is improved positioning accuracy of the method, parameters is also givenconcrete implementation method and parity generation approach.