利用σ_z(τ)方法对脉冲星时与原子时长期稳定度对比分析

The Comparative Analysis of Long-term Stability of Pulsar Time and That of Atomic Time Using σ_z(τ)

首次研究了毫秒脉冲星PSR J1939+2134共7.5a的双频计时残差序列的特征,通过分析不同行星星历对脉冲星计时精度的影响,建议使用DE421;采用σz(τ)方法估计了脉冲星时与原子时的稳定度,发现脉冲星时的稳定度一直处于上升趋势,6a高于10-15。由此可见,脉冲星时作为守时和授时的时间标准具有优势。

The characters of 7.5 a timing series of dual-frequency timing for millisecond pulsar PSR J1939 ＋ 2134 are studied for the first time. DE421 is suggested by analyzing the effects on the precision of pulsar timing with different planet ephemeris. The long-term stability of pulsar time and that of atomic time is evaluated using σz（τ） method, and it is found that the long-term stability of pulsar time is always improved with time elapsed and up to 10-15 in 6 a. Hence, pulsar time has obvious advantage as the time standard for keeping time and time service.