Comparison between frequency standards in Europe and the USA at the 10−15uncertainty level
Open accessAbstract
Istituto Elettrotecnico Nazionale Galileo Ferraris (IEN), National Institute of Standards and Technology (NIST), National Physical Laboratory (NPL), Laboratoire National de Métrologie et d'Essais—Observatoire de Paris/Systèmes de Référence Temps Espace (OP) and Physikalisch-Technische Bundesanstalt (PTB) operate cold-atom based primary frequency standards which are capable of realizing the SI second with a relative uncertainty of 1 × 10 −15 or even below. These institutes performed an intense comparison campaign of selected frequency references maintained in their laboratories during about 25 days in October/November 2004. Active hydrogen maser reference standards served as frequency references for the institutes' fountain frequency standards. Three techniques of frequency (and time) comparisons were employed. Two-way satellite time and frequency transfer (TWSTFT) was performed in an intensified measurement schedule of 12 equally spaced measurements per day. The data of dual-frequency geodetic Global Positioning System (GPS) receivers were processed to yield an ionosphere-free linear combination of the code observations from both GPS frequencies, typically referred to as GPS TAI P3 analysis. Last but not least, the same GPS raw data were separately processed, allowing GPS carrier-phase (GPS CP) based frequency comparisons to be made. These showed the lowest relative frequency instability at short averaging times of all the methods. The instability was at the level of 1 part in 10 15 at one-day averaging time using TWSTFT and GPS CP. The GPS TAI P3 analysis is capable of giving a similar quality of data after averaging over two days or longer. All techniques provided the same mean frequency difference between the standards involved within the 1σ measurement uncertainty of a few parts in 10 16 . The frequency differences between the three fountains of IEN (IEN-CsF1), NPL (NPL-CsF1) and OP (OP-FO2) were evaluated. Differences lower than the 1σ measurement uncertainty were observed between NPL and OP, whereas the IEN fountain deviated by about 2σ from the other two fountains.
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The stability and accuracy of optical links surpasses that of conventional satellite two-way time and frequency transfer by more than three orders of magnitude.
“because the stability and accuracy of optical links surpasses that of conventional satellite two-way time and frequency transfer by more than three orders of magnitude [1-3].”
From Characterization of optical frequency transfer over 154 km of aerial fiber (2017) · cites this paper as [3]
Section 4.2 compares TWSTFT with GPS-based frequency transfer, but does not assess optical links. The Conclusion mentions remote optical frequency standards, not optical links, and gives no three-orders-of-magnitude comparison. Searches for optical links and the claimed stability and accuracy advantage found no supporting passage. (LLM, conf=0.74)
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References 21 · Cited by 225
Research works printed but not linked: 6
- [11]11. Petit G and Jiang Z 2005 Stability of geodetic time links and their comparison to two-way time transfer Proc. 36th Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting (Washington, DC, 2004) pp 31-40
- [13]13. Schildknecht T, Beutler G, Gurtner W and Rothacher M 1990 Towards subnanosecond GPS time transfer using geodetic processing techniques Proc. 4th European Frequency and Time Forum (Neuchâtel, Switzerland, 1990) pp 335-46
- [19]19. see also Meindl M (ed) 2005 Proc. Celebrating a Decade of the International GPS Service-Workshop and Sympos. (Bern, Switzerland, 2004)
- [20]20. Dach R, Bernier L-G, Dudle G, Schildknecht T and Hugentobler U 2005 Geodetic frequency transfer-actual developments in the AIUB-METAS collaboration, Proc. 19th European Frequency and Time Forum (Besanc ¸on, France, 2005) at press
- [23]23. Calonico D et al 2005 Comparison between remote Cs fountain primary frequency standards Proc. 19th European Frequency and Time Forum (Besanc ¸on, France, 2005) at press
- [29]29. Douglas R J and Boulanger J S 1997 Standard uncertainty for average frequency traceability Proc. 11th European Frequency and Time Forum (Neuchâtel, Switzerland,1997) pp 345-9
- Authors
- Bauch, A., Achkar, J., Bize, S., Calonico, D., Dach, R., Hlavać, R., Lorini, L., Parker, T., Petit, G., Piester, D., Szymaniec, K., & Uhrich, P.
- Affiliations
- Physikalisch-Technische Bundesanstalt (DE)
- Observatoire de Paris (FR)
- University of Bern (CH)
- National Institute of Standards and Technology (US)
- Bureau international des poids et mesures (FR)
- National Physical Laboratory (GB)
- Venue
- Metrologia
- Publisher
- IOP Publishing
- Published
- 2005-12-22
- Volume
- 43
- Issue
- 1
- Pages
- 109-120
- ISSN
- 0026-1394 (ISSN-L)
- 1681-7575
- OpenAlex
- W2101141052
- Cited by
- 225
- References
- 21
- Citations by year
- 2026: 2 · 2025: 2 · 2024: 3 · 2023: 5 · 2022: 10 · 2021: 4 · 2020: 5 · 2019: 11 · 2018: 8 · 2017: 6 · 2016: 10 · 2015: 23 · 2014: 20 · 2013: 10 · 2012: 18
- FWCI
- 7.98
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Metrologia (publishedVersion)
- HAL (submittedVersion)
- CINECA IRIS Institutional Research Information System (IRIS Istituto Nazionale di Ricerca Metrologica) (submittedVersion)
- Funders
- National Institute of Standards and Technology
- Topics
- Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Advanced Frequency and Time Standards
- Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Scientific Measurement and Uncertainty Evaluation
- Physical Sciences › Engineering › Electrical and Electronic Engineering › Advanced Electrical Measurement Techniques
- Keywords
- frequency standard comparison, cesium fountain, hydrogen maser, two-way satellite time and frequency transfer, ionosphere-free linear combination, frequency instability, time and frequency transfer
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