LAUSR

By considering the observation samples of a hydrogen maser (HM) relative to an optical clock with time-varying variances, this article proposes an optimized predictor based on the finite impulse response (FIR) to improve the predictability of HMs. The design idea and rationality of the predictor were characterized from a theoretical viewpoint, showing its potential predictability for missing partial measurement data or unequal interval measurement data. The prediction results for simulated HMs reveal its comparable predictability with least squares method (LS). As proof of concept, it was applied to the actual data of typical HM relative to a 87Sr optical lattice clock developed by the National Institute of Metrology (NIM). Compared with the LS, the prediction error after seven days obtained by the proposed method is $\sim $ 40 ps smaller than LS.