卫星双向时间传递链路性能优化方法研究

Research on performance optimization method of two way satellite time and frequency transfer link

卫星双向时间传递(two way satellite time and frequency transfer,TWSTFT)链路的频率稳定度优于10-15量级,是国际原子时计算的重要支撑。改善TWSTFT链路24 h内的短期稳定度,对提高TAI(international atomic time)的性能具有现实意义。本文提出了一种基于Vondrak滤波的TWSTFT链路性能优化方法,首先通过频域幅值分析方法,确定符合要求的滤波因子构造Vondrak滤波器;再对中国科学院国家授时中心(National Time Service Center,NTSC)和德国联邦物理技术研究所(Physikalisch Technische Bundesanstalt,PTB)之间的时间传递结果进行处理分析,结果表明:在约化儒略日(MJD)59120-59160期间,链路测量结果滤波前后的频率稳定度平均增益为79.12%、时间稳定度平均增益为72.86%,平均时间24 h的频率稳定度、时间稳定度分别提高56.0%、59.1%;在MJD 59220-59270期间,链路的频率稳定度平均增益为85.1%、时间稳定度平均增益为70.7%,平均时间24 h的频率稳定度、时间稳定度分别提高62.4%、14.0%。该方法能够针对性地滤除链路24 h内的高频噪声,滤波后链路的准确性和稳定性都有显著提高。

The medium and long term stability of two way satellite time and frequency transfer(TWSTFT)link is better than the order of 10-14,it is an important support for international atomic time(TAI)calculation.Improving the short term stability of TWSTFT links within 24 hours has practical significance for the performance improvement of TAI.This study proposed a performance optimization method of TWSTFT link based on Vondrak filter.The required filter factors were determined by frequency domain amplitude analysis method in order to construct Vondrak filter.The time transfer results between the National Time Service Center(NTSC)of the Chinese Academy of Sciences and the German Federal Institute of Physikalisch Technische Bundesanstalt(PTB)were processed and analyzed.The results shown that during MJD 59120-59160,the average gain of frequency stability and time stability of the link were 79.12%and 72.86%.The frequency stability and time stability of 24 hours were increased by 56.0%and 59.1%respectively.During MJD 59220-59270,the average gain of frequency stability and time stability of the link were 85.1%and 70.7%.The frequency stability and time stability of 24 hours were increased by 62.4%and 14.0%respectively.The accuracy and stability of the filtered link were significantly improved by filtering the high frequency noise within 24 hours.