Objectively evaluate uncertainty of physical effect of atomic clock by noise statistical correlation method

Uncertainty is one of the most important characteristics of atomic clocks, which is obtained through a series of specific experiment evaluation of relevant physical effects. This paper presents an improved method for evaluating uncertainty contribution of some physical effects of atomic clock. Compared with previous method, the method focuses on the correlation of frequency signal of atomic clock and environmental noise signal which is recorded in the operation of atomic clock, and specific experiment is not necessary.Theoretical analysis and numerical simulations demonstrate that this method enables the measurement of sensitivity coefficients and the evaluation of associated uncertainties. Experimental demonstration was conducted on an 87 Rb fountain frequency standard, where the second-order Zeeman frequency shift and collision frequency shift were evaluated, with the result of 1 . 418 ( 47 ) × 1 0 − 13 and 1 . 44 ( 9 ) × 1 0 − 16 , respectively. The measured second-order Zeeman shift is consistent with results from previous methods within a deviation of 0.3%. The method allows real-time, concurrent uncertainty evaluation of multiple dominant systematic effects during normal operation, thereby holding significant application value in atomic clocks and precision measurement.