基于GLONASS星历的预报轨道的误差分析

Error analysis of prediction orbit determined by GLONASS ephemeris

推导了协议地球坐标系下的卫星运动方程.通过分析由GLONASS(Global Navigation Satellite System)广播星历参数确定的卫星预报轨道的拟合精度,指出了摄动力模型的简化、积分器的选择,以及忽略了极移影响等因素是引起拟合误差的主要因素,其中摄动力模型的简化起最主要的作用.通过对卫星轨道运动方程积分30 min,可知由摄动力模型的简化、积分器和忽略极移影响等因素引起的拟合误差分别为0.827 m,0.224 m和0.025 m.要提高预报轨道拟合的精度,关键是要对摄动力简化特别是地球引力摄动高阶项的截断以及日月引力场简化造成的轨道预报精度损失加以控制.

The equation of satellite orbital motion was derived in the conventional terrestrial coordinate system. By analyzing the fitting precision of satellite prediction orbit determined by GLONASS（global navigation satellite system） broadcast ephemeris, it is pointed out that the simplified models of perturbation force, the choice of numerical integration methods and the neglect of the polar motion are main factors causing the orbit fitting error, among which the simplified models of perturbation force is the most effective one. Through integrating the equation of orbital motion of satellite for 30 min, it can be found that the orbit fitting error due to the simplified force model, the numerical integration method and the neglect of the polar motion are respectively 0. 827 m, 0. 224 m and 0. 025 m. Therefore controlling the precision loss of orbital prediction cased by the simplification of models of perturbation force, especially by the truncation of high order terms of Earth gravitational perturbation and simplification of models of Sun and lunar gravitational fields can improve the fitting precision of prediction orbit.