基于星载GPS的CHAMP卫星精密简动力定轨

Precise Orbit Determination of CHAMP with Reduced-dynamic Method based on Satellite-borne GPS Technique

定轨是地球探测卫星任务顺利执行的关键。星载GPS技术提供了大量、连续的高低卫星跟踪观测,为低轨卫星精密定轨提供了技术支撑。为了确定CHAMP卫星的轨道,并分析定轨精度,利用CHAMP卫星星载GPS数据,运用零差简动力法进行精密定轨,给出了精密定轨流程。利用实际数据进行了精密定轨实验,结果与德国地学研究中心(GFZ)公布的CHAMP卫星快速轨道(RSO)进行了对比,结果显示:求解轨道可以达到厘米量级。

A great deal of continuous high-low satellite-to-satellite tracking observations can be collected with the satellite-borne GPS technique,which can be used to precisely determine orbits of low-earth-orbit satellites.CHAMP＇s precise orbit is determined from CHAMP′s satellite-borne GPS data with the zero-difference reduced-dynamic method,presents the processing of precise orbit determination and analyses the precision of orbit determintion.The experiment of precise orbit determination is done with the actual data.The result Compares with the post-processed science orbits of GFZ,and analyses the difference in X,Y,Z directions.The study shous that： the RMS difference in X,Y,Z directions are 0.053,0.054,and 0.050 m respectively.In general,the accuracy of the computed orbit is at centimeter level,and it reaches the required standard.