TY - JOUR T1 - ONCLE (One Clock Ensemble) for Galileo’s Next-Generation Robust Timing System JF - NAVIGATION: Journal of the Institute of Navigation JO - NAVIGATION DO - 10.33012/navi.536 VL - 69 IS - 3 SP - navi.536 AU - Qinghua Wang AU - Pascal Rochat Y1 - 2022/09/21 UR - https://navi.ion.org/content/69/3/navi.536.abstract N2 - This paper presents the ONCLE (One Clock Ensemble) solution for the Galileo time and frequency reference system with advanced features in terms of robustness, performance, continuity, and simplicity. Each component clock is frequency-steered to the ensemble time, which itself creates an average of those steered clock outputs, while clock faults are detected and corrected in real time within an integrated system. The feasibility of algorithm and hardware approaches has been demonstrated on an elegant breadboard and verified by an extended test and validation campaign at the Engineering Model (EM) level, developed for the Galileo next-generation onboard timing system under European GNSS Evolutions Program. Based on the progress for space application and the heritage on the Galileo ground precise timing facility (PTF), we propose a robust solution for the upgrade of PTF for ground application aiming to provide a fully continuous and performance-improved timescale under automated operation. The capability is demonstrated by preliminary simulation results. ER -