This paper analyzed the characters and rule of the satellite ephemeris error. It proposes the Model of the diagnosis and Forecast for the GPS broadcasting ephemeris error.
分析了GPS卫星星历误差的影响特征与规律，提出了广播星历误差影响诊断与预测模型。
Ephemeris error is one of the most important factors which affect positioning precision when satellite navigation was used.
广播星历误差是影响卫星导航用户定位精度的重要因素之一。
The results show that these methods are adapted well to all types of navigation satellite, and the error of the fitting ephemeris is less than several centimeters, even several millimeters.
结果表明，改进后的拟合方法能适用于各种类型的导航卫星轨道，拟合精度在厘米级或者毫米级。
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