氢钟和铯钟联合守时初探

An Initial Test on Time Keeping Through Combination of Hydrogen Maser and Cesium Clock

氢钟和铯钟作为两种不同类型的频标,从统计角度上来说,它们在短期和长期频率稳定度方面的表现为时间频率领域中的学者们共识．随着技术的改进氢钟近年来在长稳方面有所提高．根据中国科学院国家授时中心(NTSC)新进口的2台美国氢钟(Sigma T)近一年来实验数据的分析,定量说明氢钟不同采样间隔的频率稳定度,并与铯钟的性能做比较．同时根据这两种类型频标的性能取长补短,探讨一组铯钟和两台氢钟联合守时的方案和地方原子时计算方法．

It is well know that a hydrogen maser and a cesium clock show different predominance respectively in long or short term stability. As far as the long term stability is concerned, one would favor cesium clocks rather than hydrogen masers. On the contrary, the short term stability of a cesium clock is worse than that of a hydrogen maser. With the progress of technology, the long term stability of hydrogen masers has been significantly improved. In this paper, the basic theory of the noise of frequency standards is briefly de- picted. The quantitative analysis on the data of the two hydrogen masers newly imported by NTSC from U.S. Symmetricom has been compared with those of the cesium clocks of HP 5071A at NTSC. For the purpose of time keeping, the optimized way is initially seeked to the time scale algorithm with a group of hydrogen masers and cesium clocks and to the option on whether to use a hydrogen maser or a cesium clock as the frequency source in the master clock system.