摘要
提出了一种基于地心天球参考系/地球时(GCRS/TT)的地月空间激光时频传递数据处理方法,分别建立了单向和双向高精度计算模型。在此基础上,定量分析了计算模型中各误差项的量级及分布规律,并利用蒙特卡罗方法对链路误差改正项进行了敏感性分析。研究结果表明,由于单向模式的测量钟差耦合了轨道误差,双向模式性能优于单向模式,而站间单向共视模式受轨道切向误差的影响较大。当定轨三维位置精度优于150 m时,双向星地模式可以实现优于1.5 ps的链路改正不确定度和优于2×10^(-17)@10000 s的链路稳定度,站间单向共视模式对应的指标为1.7 ns和1×10^(-14)@1000 s。建立的计算模型可以对地月空间单向和双向星地激光时频传递测量数据进行高精度处理,为深空探测任务中的原子钟性能评估和时间同步提供了理论支撑。
Objective In recent years,atomic clocks have made spectacular progress,with ground-based optical lattice atomic clocks reaching stabilities of less than 10-18 and accuracies of 1×10^(-18).High-performance atomic-clock satellite-satellite,satellite-ground,and ground ground interconnections can be achieved by establishing time-frequency transfer links.This advancement provides insights into various critical technological and scientific domains,including global satellite navigation systems,deep space exploration,verification of general relativity,measurement of gravitational waves,gravity field assessment of the earth,and fundamental physical constant measurements.This year,the Chinese Academy of Sciences plans to launch a lunar orbiting spacecraft equipped with a laser timefrequency transfer payload to assess the performance of onboard hydrogen atomic clocks and to conduct a comparison of clocks in remote observatories.For high-precision time-frequency transfer data processing,establishing a computational model that meets the requirements of the mission within the framework of general relativity is necessary.Methods Based on the existing relativistic theory for time and frequency transfer,in this study,we derived a relativistic model of one-and two-way satellite-ground laser time-frequency transfer on a distant retrograde orbit(DRO),which can be directly used in the data processing of the DRO laser time-frequency transfer.Using the simulated DRO orbit,we analyzed the magnitudes and distribution patterns of various error correction terms in the laser time-frequency transfer.These terms include light-time correction,atmospheric refraction,relativistic rate shifts,and position correction between the detector and reflector.In addition,Monte Carlo methods were employed to simulate and compute the uncertainties of link corrections,considering the DRO orbit and attitude determinations and the probe payload calibration parameters.The effects of these uncertainties on the stability and accuracy of the time-frequency transfer measurements were investigated for both one-and two-way satellite-ground modes and for one-way laser timefrequency transfer in the common-view mode.Results and Discussions In the two-way mode,the dependence on the satellite orbit accuracy is relatively weak.With a radial distance error in orbit determination of 10 m,we anticipate that the accuracy of link error correction will exceed 1.5 ps,with corresponding link stability(modified Allan deviation)of better than 2×10^(-17)@10000 s.However,the comparative performance of the one-way mode is highly dependent on the accuracy of the satellite orbit determination.The measurement clock error is coupled with the orbit errors.In scenario 1,the link correction accuracy is expected to be within 38 ns,with corresponding link stabilities of approximately 8×10-15@1000 s and 7×10^(-14)@10000 s.This may affect the assessment of the long-term stability of onboard hydrogen clocks.Correction of the detector–reflector positioning relationship is a major factor that affects the laser time-frequency transfer in lowearth-orbit satellites.In lunar laser time-frequency transfer,assuming ground measurement errors of 1 cm and attitude measurement errors of 360 arcsec,the correction uncertainty is approximately 1×10^(-13).Both one-and two-way modes require correction for atmospheric refraction,with the one-way mode possibly requiring more accurate meteorological parameters than the two-way mode.When two observation stations each use one-way mode to conduct measurements on a DRO probe and achieve one-way laser time-frequency transfer in the common-view mode,the link is expected to achieve an accuracy of better than 1.7 ns and a stability of 1×10^(-14)@1000 s.Conclusions The computational model developed in this research enables high-precision processing of one-way and two-way laser time-frequency transfer measurement data between the earth and the moon,thereby providing a theoretical foundation for the performance evaluation of atomic clocks and time synchronization in deep space exploration missions.
作者
耿仁方
吴志波
黄勇
孟文东
汤凯
张海峰
刘通
王文彬
张忠萍
Geng Renfang;Wu Zhibo;Huang Yong;Meng Wendong;Tang Kai;Zhang Haifeng;Liu Tong;Wang Wenbin;Zhang Zhongping(Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China;Technology and Engineering Centre for Space Utilization,Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Space Object and Debris Observation,Chinese Academy of Sciences,Nanjing 210008,Jiangsu,China)
出处
《中国激光》
北大核心
2025年第2期122-133,共12页
Chinese Journal of Lasers
基金
中国科学院战略性先导科技专项(XDA30040500,XDA30030500)
国家自然科学基金(12373085)
科工局民用航天技术预先研究项目(D010105)。
关键词
卫星激光测距
激光时频传递
地月空间
绕月远距离逆行轨道
satellite laser ranging
laser time-frequency transfer
cislunar space
distant retrograde orbit(DRO)
