高精度连续时频信号产生和控制系统的分析

Analysis on the System for Generating and Controling Highly Precise Uninterrupted Time and Frequency Signals

具体分析了NTSC和LORAN-C的两套时频基准系统。结果表明,NTSC时频基准系统可以产生高精度的时间频率信号,但是没有主标备份,不利于连续性的保持;而LORAN-C的时频基准系统产生控制高精度时频信号,同时主标发生故障时自动切换到副标,不停止信号的输出,而且切换主标时不会发生信号瞬间中断或相位突变,这些又保证了信号的瞬间连续性。它可广泛应用于守时、授时及导航系统中。

Two standard time and frequency systems used in the National Time Service Center （NTSC） and Loran - C are analyzed fully in this paper. The result shows that the system in NTSC gen- erates and controls highly precise time and frequency signal, but it is disadvantage to keeping continuity without the major frequency standard backup, and the system in Loran - C can generate and control highly precise time and frequency signal, at the same time the major frequency standard is switched to another automatically when it is malfunction, which dose not stop the output signal, moreover, there are not the signal interruption and the phase leap at the moment of switching the major frequency standard, which ensures the instantaneous continuity of the signal. The latter can be widely used in time keeping time service and navigation systems.