Practical performance of the UTC(CH.R) real time realization of UTC(CH) and prospects for improvement

UTC(CH.R) is a hardware real-time realization of UTC(CH) generated from the reference cesium clock by means of a micro-phase-stepper. The purpose of the steering algorithm is to keep UTC(CH.R) as close as possible to UTC(CH) by means of a time-frequency control loop which must be stable despite the delay of 1 d between the epoch of the last computed state and the epoch of the daily steering. The paper presents the practical performance of the UTC(CH.R) realization based on measurement data recorded from April 2002 to April 2003. The performance of the UTC(CH.R) steering algorithm is compared against simulation results that apply alternative steering algorithms to the same free running clock data. In conclusion plans to use a hydrogen maser instead of a cesium clock for the generation of a future, improved UTC(CH.R) are discussed.