一种针对氢原子频标长稳测量的修正阿伦方差算法研究

Research on a Modified Allan Variance in the Long-term Frequency Stability Measurement of Hydrogen Frequency Atom Standard

频率稳定度是氢原子频标内部噪声随机起伏程度的定量描述。文章阐述了阿伦方差作为频率稳定度时域表征的原因,分析了频率漂移对氢原子频标长期稳定度测量的影响,针对此问题,介绍了一种修正的阿伦方差算法。基于最小二乘法估计频率漂移率,定量反映输出频率的漂移规律,并在阿伦方差理论公式的基础上扣除频率漂移引入的系统差。以守时实验室实测时差数据对修正算法进行验证,分析结果表明,修正算法能有效地扣除频率漂移的影响,可应用于氢原子频标的长期稳定度测量中。

Frequency stability is a quantitative description of the random fluctuation degree of noise in hydrogen frequency atom standard. This article expounds the Allan variance as the cause of the frequency stability time domain representation,and analyses the influence of frequency drift in long-term frequency stability measurement of the hydrogen atom frequency standard,according to this problem,this paper introduces a modified Allan variance algorithm. Based on the least square method to estimate the frequency drift rate,quantitatively reflect the output frequency drift rule,and deduct the system difference introduced by the frequency drift in the Allen variance theory formula. The modified algorithm is validated by the measured time difference data of punctual laboratory,the analysis results show that the modified algorithm can effectively to deduct the influence of the frequency drift,and can be applied to long-term frequency stability measurement of the hydrogen atom frequency standard.