Research on Broadcast Ephemeris Parameters Fitting Algorithm Based on the First Class of No Singularity Variables
Wang Hai-hong · Spacecraft Engineering · 2011
Broadcast ephemeris parameters are an important part of the navigation message,and usually can be obtained by parameter fitting the precise ephemeris.Most scholars adopt broadcast ephemeris parameters fitting algorithm based on Kepler elements,but research shows that the fitting accuracy of this method is poor in the case of small eccentricity.This paper gives broadcast ephemeris parameters fitting algorithm based on the first class of no singularity variables.The simulation shows that the algorithm can effectively avert the fitting accuracy loss caused by small eccentricity,fitting accuracy can reach millimeters;In addition,this paper discusses the adaptability of the algorithm in the case of small inclination,the simulation shows that the fitting algorithm is not suitable for small inclination.In the end,combining with the engineering application of autonomous navigation,this paper analyzes the extrapolation capability of navigation data and gives an initial scheme in which the fitting arc length of autonomous navigation data is for 2 hours,and the update interval is 15 minutes.