轨道误差对空间站高精度时间比对的影响分析及修正方法

Effect of Orbit Error on Space Station Time Comparison and Calibrating Method

针对空间站飞行轨道的特点,从理论上分析了空间站轨道误差对单向和共视时间比对的影响,并通过仿真试验对理论分析结果进行校验,研究结果表明轨道误差对空间站时间比对的影响在几百皮秒量级,是影响空间站时间比对精度的主要误差源。提出一种适用于两个地面站间进行高精度时间比对的空间站轨道误差修正方法,通过仿真试验校验了该方法的有效性。试验结果表明,该方法能有效修正空间站轨道误差,实现精度在几十皮秒量级的两地面站间的超高精度时间比对,比对基线可达上千千米。

According to the characteristics of the space station orbit, the effect of space station orbit error on the one way and common-view time comparison is analyzed both in theory and simulation firstly. The research result shows that the effect of orbit error on time comparison is about several hundred picoseconds, and it is the main error source that restricts the time comparison accuracy to be improved. Then, an appropriate orbit error calibrating method that is based on the position relationship between the space station and two ground stations is introduced. Additionally, the high stability of the space and ground atomic clocks is advantaged to model and extrapolate the space-ground clock bias. The geometric position relationship and the modeling and extrapolating of the space-ground clock bias are combined together to solve the problem of orbit error. Finally, some simulation experiments are done to validate the proposed method. The experiment results show that the method is effective and the time comparison accuracy is great improved to be several ten picoseconds, the baseline is up to the magnitude of thousand kilometers.