Swarm系列卫星非差运动学厘米级精密定轨

Abstract

采用2015年5月24日—30日的Swarm星载GPS双频观测数据，基于Melbourne-Wübbena（MW）和消电离层线性组合，在精密单点定位技术的基础上，采用批处理最小二乘估计法对不同轨道高度的Swarm系列卫星进行非差运动学精密定轨。利用星载GPS相位观测值残差、与欧空局发布的简化动力学轨道对比，以及SLR检核3种方法对Swarm系列卫星非差运动学定轨结果进行精度评估。结果表明：①Swarm系列卫星星载GPS相位观测值残差RMS为6~7 mm；②与欧空局发布的简化动力学轨道进行求差，径向、切向及法向轨道差值RMS为2~4 cm；③与欧空局发布的运动学轨道进行求差，径向、切向及法向轨道差值RMS为1~2 cm；④SLR检核结果表明Swarm-A/B/C卫星轨道精度为3~4 cm。因此，采用非差运动学定轨方法与本文提供的定轨策略进行Swarm系列卫星精密定轨是切实可行的，定轨精度为厘米级。

Alternate abstract:

Using dual-frequency satellite-borne GPS observations from May 24 to May 30, 2015, the linear combination of Melbourne-Wübbena and ionosphere-free linear combination, based on the basis of precise point positioning technology, the batch least squares estimation method is used to precisely determine the Swarm undifferenced kinematic orbits with different orbital attitudes. The orbit accuracy is assessed using three methods, which include satellite-borne GPS phase observation residuals analysis, comparison with ESA reduced-dynamic orbits and external evaluation with SLR measurements. The results indicate: ①Swarm satellite-borne GPS phase observation residual RMS is in the range of 6~7 mm level. ②Comparisons with reduced-dynamic orbits computed by European Space Agency (ESA), radial, along-track and cross-track orbit difference RMS are in the range of 2~4 cm level. ③Comparisons with kinematic orbits computed by ESA, Radial, along-track and cross-track orbit difference RMS are in the range of 1~2 cm level. ④The external validation with satellite laser ranging (SLR) measurement shows RMS errors are in the range of 3~4 cm level. Therefore, it is feasible to use the undifferenced kinematic orbit determination method and the orbit determination strategy provided in this paper to carry out the precise orbit determination of swarm series satellites. The orbit determination accuracy is centimeter level.