Real time synchronisation of a free-running atomic clock time base with UTC using GNSS signals for application in experimental physics

TL;DR

This paper demonstrates a real-time method to synchronize a free-running atomic clock with UTC using GNSS signals, achieving residual differences within ±15 ns without residual drift, applicable in experimental physics.

Contribution

The paper introduces the first real-time application of a GNSS-based correction method to synchronize atomic clocks with UTC, improving precision in timekeeping.

Findings

Residual difference within ±15 ns from UTC

No residual drift observed over time

Effective with both Rubidium and Cesium clocks

Abstract

We present the results obtained by applying, in real-time, a correction method to precisely synchronize a time base generated from a free-running atomic clock with the Coordinated Universal Time (UTC). The method uses the Global Navigation Satellite System (GNSS) signals to have regular time comparisons between the atomic clock generated time base and the GPS Time, perform linear fits of the measurements and extrapolate a correction to apply to the free-running signal. In this work, we apply for the first time this method in real-time. Two atomic clocks were tested, a low-cost Rubidium clock and a more expensive magnetic Caesium clock. We demonstrate that we can obtain a residual difference between the clock time base and the French official realization of UTC (UTC(OP)) in the range of $\pm 15$ ns with no apparent residual drift.