Clock prediction and characterization

Abstract

In this paper we describe the application of linear predictors to the metrology of clocks, to time-scale generation and to the characterization of clocks in terms of their predictability. The ideas are general and can be applied to other fields of metrology in which very precise measurement techniques are used to reveal an unstable and time-dependent measurand. In such measurements, it is important to make the best possible prediction of the next measurements. If the prediction uncertainty is small then the measurand is meaningful and useful. Prediction need not be linear. However, in the case of clocks, linear predictors are optimal or close to optimal for the prediction of clock instablilities modelled by the oscillator noise model superimposed on frequency drifts and accelerations.