A Timescale Based on the World’s Fountain Clocks

G. Petit

Abstract:	International Atomic Time TAI gets its accuracy from a small number of primary frequency standards (PFS), based on the Cs transition defining the second, which are operated in a few time laboratories. Cold-atom Cs “fountains” started to regularly contribute as PFS in 1999 and some ten such fountains are now providing data more or less frequently. A Rb fountain started reporting as a secondary frequency standard (SFS) in 2012 and has regularly continued since that time. In addition, four Rb fountains have also been continuously reported as clocks participating to the TAI clock ensemble since the end of 2011. Because some of the PFS and SFS fountains are also operated nearly continuously it turns out that since early 2012 the number of available fountains is sufficient to process them through a stability algorithm to generate a timescale. The performance of such an ensemble fountain timescale is estimated and its use to evaluate TAI and TT(BIPM) is considered.
Published in:	Proceedings of the 45th Annual Precise Time and Time Interval Systems and Applications Meeting December 2 - 5, 2013 Hyatt Regency Bellevue Bellevue, Washington
Pages:	265 - 268
Cite this article:	Petit, G., "A Timescale Based on the World’s Fountain Clocks," Proceedings of the 45th Annual Precise Time and Time Interval Systems and Applications Meeting, Bellevue, Washington, December 2013, pp. 265-268.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In