Abstract: It is comparison among remote clocks that is a necessary condition of establishing joint atomic timescale using atomic clocks in different laboratories, so the noise level of high precision time transfer technology, which is used to compare among remote clocks, becomes one of the main factors influencing the performance of atomic timescale. This paper mainly studied the low-pass filtering method based on empirical mode decomposition, and its application for de-noising of the remote clocks comparing data. And it is made to compare this method with Vondrak smoothing one. The results indicate that the lowpass filter results based on the empirical mode decomposition is better than Vondrak smooth ones.

Key words: Clock Comparison, Empirical Mode Decomposition, The time-space filter