利用GPS非差观测值的GRACE卫星精密定轨

Precise Orbit Determination of GRACE Satellite with Un-differential GPS Measurements

参照GPS精密单点定位(PPP,Precise Point Positioning)模型设计了一种新的卫星定轨方法-组合星载加速度计测量数据和IGS提供的GPS精密星历及精密钟差数据进行低轨卫星的精密定轨。利用星载加速度计提高卫星受力模型准确性,使动力法定轨精度和可靠性都得到提升。同时,采用多种改正技术提高GPS非差观测值测量精度,保证最终高精度卫星定轨。本文建立了卫星定轨的轨道滤波模型,得出了有益的结论,即采用星载加速度计测量卫星非保守力可提高卫星定轨精度,在ITRF2000参考系下三轴精度优于18cm。这种方法不需要在全球建立基准观测站,定轨设备简单,费用低廉。

The paper presented a new method for LEO satellite precise orbit determination by referring to PPP（Precise Point Positioning） method-Which integrated Onboard accelerometer data and GPS precise ephemeris and clock error data provided by the IGS. The accuracy of force models acting on satellite can be improved with the onboard accelerometer, and which then increased the accuracy and reliability of orbit determined by the dynamic method. Several methods have been adopted to increase the precision of GPS un-differential measurements, which ensured the high precision of orbit determination. The paper established the orbit filter model and has achieved useful conclusions that the precision of satellite orbit can be improved with the high level forces partly measured with onboard accelerometer. The precision of three axis is below 18cm under the ITRF2000 reference frame. The method using simple and low cost device can complete the orbit determination without any GPS base stations.