The on-board Galileo clocks: Rubidium standard and Passive Hydrogen Maser - current status and performance

Galileo program is approved by the European Commission and the European Space Agency (ESA). The activities related to GSTBV2 experimental satellite provide the first results and the implementation of the In Orbit Validation (IOV) phase are in progress. Atomic clocks represent critical equipment for the satellite navigation system and clocks development has been continuously supported by ESA. The Rubidium Atomic Frequency Standard (RAFS) and the Passive Hydrogen Maser (PHM) are at present the baseline clock technologies for the Galileo navigation payload. This article gives a general overview on the RAFS and the PHM developments and evolution up to now. It also provides updated information on the performance measurement results on ground and the preliminary information available related to the In Orbit behavior.