北斗卫星多天轨道合成方法及其精度分析

Solution Method and Precision Analysis of Multi-days Orbit Combination of BeiDou Satellites

目前,北斗卫星多天解轨道主要是通过常规的数据累积解算获得,处理效率较低。此外,由于开通运行不久,北斗卫星力学模型尚未完善,限制了多天解轨道精度的进一步提高。针对以上问题,本文提出了附加伪随机脉冲的北斗卫星多天轨道合成方法,利用法方程叠加实现北斗卫星多天轨道合成,可有效提高轨道解算效率。同时,利用伪随机脉冲对力学模型的补偿作用,进一步提高了多天轨道合成的精度水平。实测数据分析表明:在多天轨道合成中,单天边界附加伪随机脉冲对北斗卫星轨道精度有明显改进作用。其中,3类卫星切向、法向轨道精度的改善程度大于径向,GEO和IGSO卫星轨道精度的提高幅度大于MEO卫星。一定范围内,随着定轨弧段的增长,北斗卫星定轨精度能够得到不同程度的改善,且主要表现在轨道切向。

Multi-days orbit of BeiDou satellites is gotten by the routine method of stacking observation data at present,which limits calculation efficiency.And moreover,the dynamic model of BeiDou satellites is not perfect because of the short running time,which also limits the precision of multi-days orbit.The method of multi-days BeiDou satellite orbit combination is present.In this method,normal equation stacking is used to combining some consecutive one-day BeiDou satellite orbits to one multi-days orbit,which can improve calculation efficiency.Meanwhile,pseudo-stochastic pulse is used to compensate the deficiency of dynamic model.The analysis shows that it is the pseudo-stochastic pulse at one-day boundary that improves the precision of BeiDou satellite orbits obviously.And the tangential and normal precision is improved more than the radial.The orbit precision of GEO and IGSO is improved more than that of MEO.And the precision of BeiDou satellite orbit can be improved by extending the orbit arc length with certain limits,which is especially in the tangential direction.