轨道动力学修正模型及其在北斗短时星历预测中的应用

Orbital Dynamics Correction Model and Application in Short-term Ephemeris Prediction of Beidou Navigation Satellites

对于具有低功耗和小型化需求的便携式卫星导航终端设备,准确的星历预测更有利于其快速定位,实现节能与器件小型化.在传统卫星轨道动力学模型预测方法的基础上,提出了含太阳、地球和月球的万有引力以及太阳光压之外的其他摄动力修正项的修正模型.利用导航卫星轨道位置的周期性特性,在轨道平面下对该修正项进行数值建模,通过北斗导航卫星的历史广播星历数据获得修正项参数的短时拟合值,进而对北斗导航卫星进行星历预测.最后,通过北斗导航卫星的实际星历数据验证了该修正模型对提高短时星历预测精度的可行性.

For portable navigation devices that require strict power consumption and miniaturization,it＇s important for fast fix to obtain accurate orbit prediction.In this paper,a novel short-term ephemeris prediction approach of Beidou Navigation satellites is proposed.Based on the traditional force model,the periodical relationship between satellite coordinates and the secondary perturbing forces is modeled numerically.Parameters in the proposed model can be derived from historical broadcast ephemeris,and then used in short-term prediction to improve the accuracy of orbit prediction.The proposed approach is evaluated by the real data broadcasted by BDS satellites,and the results show the improvement of orbit prediction accuracy is significant.