国产SOHM-4型氢钟长期性能分析

Long term performance analysis of domestic SOHM-4 hydrogen clock

针对目前对国产氢原子钟性能评估,尤其是对国产氢钟长期在线运行性能评估相对缺乏的问题,提出1种氢钟性能评估方法:以上海天文台研制的国产SOHM-4型氢钟为例,基于连续相位比,对数据对其性能进行评估;通过分析由频率准确度、频率漂移率和频率稳定度指标组成的评估模型,达到对国产氢钟长期在线运行性能精确评估的目的。结果表明,在长达2 a多的连续运行中,国产SOHM-4型氢钟的频率准确度基本优于5×10^-13、频率漂移率优于1×10^-14/d,且线性关系不明显,频率稳定度在±2.5℃温差环境影响下,以天稳计算,大概率处于1×10^-14~2×10^-14之间。

Aiming at the problem that it is lack of the performance evaluation,especially the long-term online operation performance evaluation for domestic hydrogen atomic clocks,the paper proposed an evaluation method of hydrogen clocks:taking SOHM-4 hydrogen clocks developed by Shanghai Astronomical Observatory as an example,the performance was evaluated based on the continuous phase comparison data;and the evaluation model composed of the indexes of frequency accuracy,frequency drift rate and frequency stability was analyzed,so as to precisely evaluate the long-term online operation performance of domestic hydrogen clocks.Results showed that:during more than two years’continuous operation,the frequency accuracy of the domestic clock would be basically better than 5×10^-13,while the frequency drift rate would be better than 1×10^-14/d with an unconspicuous linear relationship;and the daily frequency stability would be between 1×10^-14 and 2×10^-14 with a high probability under the influence of±2.5℃temperature difference.