广播星历参数拟合是建立卫星导航系统的一项关键技术,星历用户算法的简洁高效直接决定了用户导航定位的效率。在基于GEO、IGSO和MEO三类卫星的北斗二代导航定位系统中,GEO卫星的广播星历参数拟合是迫切需要解决的难点之一。基于广播星历参数的最小二乘解法,推导出了轨道面旋转角对广播星历参数的影响表达式,分析了轨道面旋转角的大小对广播星历参数拟合稳定性的影响。计算结果表明,通过增加轨道面旋转角不仅很好地解决了GEO卫星广播星历参数超限的问题,而且确保了广播星历参数拟合算法的精度和可靠性。
Reliable fitting of broadcast ephemeris parameters is a key technique to build the satellite navigation system. The efficiency of user navigation and positioning is directly lying on the briefness and high efficiency of the ephemeris user algorithm. The broadcast ephemeris parameter fitting of GEO satellites is a difficult problem urgent to be solved in Compass system construction. The influence formula of the orbital plane rotation angle on the broadcast ephemeris parameters is deduced and main factors determining the calculated value of the influence function are analyzed based on the least square fitting solution of the broadcast ephemeris parameters. And the effect of the orbital plane rotation angle on the ephemeris fitting algorithm stability is analyzed. The calculation results show that not only the overrange problem of the GEO satellite broadcast ephemeris parameters can be solved but also accuracy and reliability of the broadcast ephemeris parameter fitting algorithm can be insured by increasing the orbital plane rotation angle.