不同姿态控制模式下的北斗卫星定轨策略研究

Orbit Determining Strategy Analysis for BeiDou Satellite in Different Attitude Control Modes

北斗卫星的姿态控制分为动态偏置、零偏置和连续动偏3种,不同类型卫星、不同姿态控制模式、不同时段下定轨精度不一致,影响了北斗系统的连续性。详细研究了北斗不同类型卫星在不同姿态控制模式下的最优定轨策略,并基于实测数据进行试验,结果表明,BeiDou-2 IGSO(inclined geosynchronous orbit)/MEO(medium earth orbit)卫星采用基于星地钟差约束下多星定轨方法和ECOM(extended CODE model)5参数模型相结合的方法定轨精度最优,零偏期间,用户等效距离误差值为2.08 m,全球激光评估轨道视向精度约为1 m;BeiDou-3 IGSO/MEO卫星采用常规多星定轨和ECOM 5参数模型相结合的方法定轨精度最优;连续动偏期间,用户等效距离误差值为1.22 m,全球激光评估轨道视向精度为0.23 m,与动偏期间精度一致;GEO(geostationary earth orbit)卫星在春秋分附近时段采用基于星地钟差约束下多星定轨方法和ECOM 9参数模型相结合的方法定轨精度最优,用户等效距离误差值为0.72 m。

The BeiDou navigation satellite system have three attitude control modes-yaw-steering(YS)mode,orbit-normal(ON)mode and continuous yaw-steering(CYS)mode.The orbit accuracy and best orbit determination projects for different satellites were a hot topic at present in different time and different attitude control mode,which are researched and whose the dynamical mechanisms is analyzed in this paper.The results are as follows.For BeiDou-2 satellites,multi-satellite precise orbit determination by fixing satellite/station clock offset and extended CODE model(ECOM)5 SRP should be the best project,user equivalent range errors(UERE)root mean square(RMS)in ON mode is 2.08 m,global satellite laser ranging(SLR)data fitting RMS is ablout 1 m.For BeiDou-3 satellites,multi-satellite precise orbit determination and ECOM 5 SRP should be the best project,UERE RMS in CYS mode is 1.22 m,SLR data fitting RMS is 0.23 m,which is comparable to that in YS mode.For GEO satellites near spring or autumn equinox,multi-satellite precise orbit determination by fixing satellite/station clock offset and ECOM 9 SRP should be the best project,UERE RMS is 0.72 m.