【摘要】 中国综合定位导航授时（positioning navigation timing, PNT）体系是以北斗卫星导航系统（BeiDou navigation satellite system, BDS）为核心的多源信息融合系统,高精度的毫秒脉冲星计时能够增强BDS时间基准的长期稳定性,并能维持未来深空用户的时间基准.本文提出了一种改善BDS时间基准长期稳定性的脉冲星时地面服务系统,概述了该系统的初步设计与功能,同时研究了天地基脉冲星时建立方法,利用3颗毫秒脉冲星的国际脉冲星计时阵（international pulsar timing array, IPTA）地面射电、"中子星内部成分探测器"（neutron star interior composition explorer, NICER）空间X射线计时数据以及500 m口径球面射电望远镜（five-hundred-meter aperture spherical radio telescope, FAST）模拟数据,分析了天地基脉冲星时的稳定性.研究结果表明,基于IPTA数据的PSR J0437-4715地基脉冲星时的年稳定度为3.30×10^–14, 10年的稳定度为1.23×10^–15.脉冲星红噪声会降低脉冲星时稳定性, PSR J1939+2134地基脉冲星时的年稳定度为6.51×10^–12.同时研究发现脉冲到达时间（time of arrival, TOA）的精度是制约天基脉冲星时稳定性的重要因素,基于NICER空间X射线计时数据的PSR J1824-2452A天基脉冲星时年稳定度为1.36×10^–13.最后模拟分析了FAST将来对脉冲星时的贡献,在不考虑红噪声的影响下,基于FAST的PSR J1939+2134地基脉冲星时的年稳定度为2.55×10^–15, 10年稳定度为1.39×10^–16, 20年稳定度为5.08×10^–17,显示了FAST强大的脉冲星观测能力. FAST计时观测将有力地提升中国地基脉冲星时系统建设水平,也能增强中国综合PNT系统时间基准的长期稳定性.更多还原

【Abstract】 The comprehensive positioning navigation timing（PNT） system in China is a multi-source information fusion system with BeiDou navigation satellite system（BDS） as a core. The high-precision millisecond pulsar timing can enhance the long-term stability of the BDS time benchmark and maintain a space-time benchmark for future deep-space users. In this paper, a ground-based pulsar time service system is proposed for detecting and improving the time benchmark of BDS. The preliminary designs and functions of the system are outlined.At the same time, the method of establishing space and ground-based pulsar time is studied. The ground radio timing data from the international pulsar timing array（IPTA）, the X-ray timing data from the neutron star interior composition explorer（NICER） in space, and the simulation data from the 500-meter spherical radio telescope（five-hundred-meter aperture spherical radio telescope, FAST） for three millisecond pulsars are used to analyze the stability of ground/space-based pulsar time. The research results are as follows. The annual stability of the PSR J0437-4715 ground-based pulsar time based on IPTA data is 3.30 × 10^–14, and the 10-year stability is 1.23 × 10^–15, respectively. The existence of pulsar red noise can reduce the time stability of the pulsar. The annual stability of the PSR J1939+2134 ground-based pulsar time is 6.51 × 10^–12. We find that the accuracy of the pulse time of Arrival（TOA） is an important factor that restricts the stability of space-based pulsar time. Based on NICER space X-ray timing data, the stability of the pulsar time for PSR J1824-2452A is 1.36 × 10^–13 in one year. Finally, the simulation analysis of the FAST’s data without considering the influence of red noise is completed, and we find that the PSR J1939+2134 ground-based pulsar time based on the FAST has an annual stability of 2.55 × 10^–15, a 10-year stability of 1.39 × 10^–16, and a 20-year stability of 5.08 × 10^–17.It demonstrates that the powerful pulsar observation capability of FAST will help to improve the accuracy of ground-based pulsar time and enhance the long-term stability of the comprehensive PNT system time benchmark in China.更多还原