基于改进型第二类无奇点根数的北斗GEO卫星广播星历拟合算法及实现

Broadcast Ephemeris Fitting Algorithm and Realization of BeiDou GEO Satellite Based on Improved Second-class Nonsingular Orbital Elements

针对北斗GEO卫星广播星历的拟合及用户算法需要进行轨道面旋转的情况，本文采用一种改进型第二类无奇点根数来代替原有的广播星历参数，给出了用户算法，推导了卫星三维坐标对无奇点根数的偏导数，并利用最小二乘算法对无奇点根数进行了拟合。北斗GEO实测轨道数据试验结果表明，该算法能很好地解决北斗GEO卫星小倾角和小偏心率所带来的拟合失败问题，且16参数的拟合精度优于0．1m。

Since the rotation of reference plane is required by BeiDou GEO satellite broadcast ephemeris fitting and user al- gorithm, improved second-class nonsingular orbital elements are used to replace the original broadcast ephemeris parameters, and the user algorithm is proposed. Then the partial derivative of three dimensional coordinate of satellite to nonsingular orbital ele- ments is derived, and second-class nonsingular orbital elements are fitted using least square algorithm. The experiment results of BeiDou GEO measured data show that the algorithm can solve the problem of fitting failure caused by the small inclination angle and small eccentricity of BeiDou GEO satellite, and the fitting accuracy of the 16 parameters is better than 0. 1m.