International timescales with optical clocks (ITOC)

Helen S. Margolis, Rachel M. Godun, Patrick Gill, L. A. M. Johnson, Setnam L. Shemar, Peter B. Whibberley, Heiner Denker, Ludger Timmen, Christian Voigt, Davide Calonico, Filippo Levi, Luca Lorini, M. Pizzocaro, Stephan Falke, Dirk Piester, Christian Lisdat, Uwe Sterr, Stefan Vogt, Stefan Weyers, Pacôme DelvaSébastien Bize, Joseph Achkar, Jan Geršl, Thomas Lindvall, Mikko Merimaa

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

21 Citations (Scopus)


A new collaborative European project "International timescales with optical clocks" (ITOC) aims to tackle the key challenges that must be addressed prior to a redefinition of the SI second. A coordinated programme of comparisons will be carried out between European optical clocks developed in five different laboratories, enabling their performance levels to be validated at an unprecedented level of accuracy. Supporting work will be carried out to evaluate relativistic effects that influence the comparisons, including the gravitational redshift of the clock transition frequencies. A proof-of-principle experiment will also be performed to demonstrate that optical clocks could be used to make direct measurements of the Earth's gravity potential with high temporal resolution.
Original languageEnglish
Title of host publication2013 Joint European Frequency and Time Forum & International Frequency Control Symposium (EFTF/IFC)
PublisherIEEE Institute of Electrical and Electronic Engineers
ISBN (Electronic)978-1-4799-0342-9 , 978-1-4799-0341-2
Publication statusPublished - 2013
MoE publication typeA4 Article in a conference publication
EventJoint European Frequency and Time Forum and International Frequency Control Symposium, EFTF/IFC 2013 - Prague, Czech Republic
Duration: 21 Jul 201325 Jul 2013


ConferenceJoint European Frequency and Time Forum and International Frequency Control Symposium, EFTF/IFC 2013
Abbreviated titleEFTF/IFC 2013
Country/TerritoryCzech Republic


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