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14 - International Atomic Time (TAI)

Published online by Cambridge University Press:  01 October 2018

Dennis D. McCarthy
Affiliation:
United States Naval Observatory
P. Kenneth Seidelmann
Affiliation:
University of Virginia
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Summary

As atomic clocks became available in laboratories and observatories around the world atomic timescales were developed. The Bureau International de l'Heure began an atomic time scale in July 1955 based on clock comparisons at other locations. The IAU recommended a unification of an atomic timescale in 1967, and in 1971, the Conférence Générale des Poids et Mesures (CGPM) requested the definition of International Atomic Time (TAI), and the methods and weighting for the determination of TAI have evolved over the years along with the organizations participating in the process. Coordinated Universal Time (UTC) differs from TAI by integral seconds, so that TAI can be accessed through the international standard UTC. TAI can be considered as a realization of Terrestrial Time (TT).
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Publisher: Cambridge University Press
Print publication year: 2018

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References

Arias, E. F. (2012). Perspective: Time Scales and Clocks: Invited Review Article: The Statistical Modeling of Atomic Clocks and the Design of Time Scales. Review of Scientific Instruments, 83, 020901.CrossRefGoogle ScholarPubMed
Arias, E. F. (2014). Atomic Time Scales for the 21st Century. Rev Mex AA(Serie de Conferencias), 43, 2934.Google Scholar
Audoin, C. & Guinot, B. (2001). The Measurement of Time. Cambridge: Cambridge University Press.Google Scholar
Azoubib, J., Granveaud, M., & Guinot, B. (1977). Estimation of the Scale Unit Duration of Time Scales. Metrologia, 13, 8793.CrossRefGoogle Scholar
Barnes, J. A., Andrews, D. H., & Allan, D. W. (1965). The NBS-A Time Scale: Its Generation and Dissemination. IEEE Trans. Instrum. Meas., IM, 14, 228232.CrossRefGoogle Scholar
Bureau International de l’Heure (1974). BIH Annual Report for 1973. Observatoire de Paris (in French; English version appears in BIH Annual Report for 1974, published in 1975).
Bureau International des Poids et Mesures (2006). The International System of Units (SI). Eighth Edition. Paris: Bureau International des Poids et Mesures.
Bureau International des Poids et Mesures (2016). BIPM Annual Report on Time Activities Volume 10 2015. Paris: Bureau International des Poids et Mesures.
Comptes Rendus de la 14e CGPM (1971) (1972). 78, available at www1.bipm.org/en/convention/cgpm/resolutions.html.
Comptes Rendus de la 15e CGPM (1975) (1976). 104, available at www1.bipm.org/en/convention/cgpm/resolutions.html.
Comptes Rendus de la 18e CGPM (1987) (1988). 98, available at www1.bipm.org/en/convention/cgpm/resolutions.html.
Essen, L. Time for Reflection. Published privately and available at www.btinternet.com/~time.lord/ also available in Henderson, D. (2005). Essen and the National Physical Laboratory’s Atomic Clock. Metrologia, 42 S4S9.Google Scholar
Essen, L. & Parry, J. V. L. (1957). The Caesium Resonator as a Standard of Frequency and Time. Philos. Trans. Roy. Soc. London. Ser. A, Mathematical and Physical Sciences, 250, 4569.CrossRefGoogle Scholar
Giacomo, P. (1981). News from the BIPM. Metrologia, 17, 6974.CrossRefGoogle Scholar
Giacomo, P. (1988). News from the BIPM. Metrologia, 25,113119.CrossRefGoogle Scholar
Guinot, B. (1988). Atomic Time Scales for Pulsar Studies and Other Demanding Applications. Astron. Astrophys, 192, 370373.Google Scholar
Guinot, B. & Arias, E. F. (2005). Atomic Time-Keeping from 1955 to the Present. Metrologia, 42, S20S30.CrossRefGoogle Scholar
Levine, J. (2012). The Statistical Modeling of Atomic Clocks and the Design of Time Scales. Review of Scientific Instruments, 83, 021101.CrossRefGoogle ScholarPubMed
Markowitz, W. (1962). IRE Trans. Instrum., I -11, 239242.CrossRef
Nelson, R. A., McCarthy, D. D., Malys, S., Levine, J., Guinot, B., Fliegel, H. F., Beard, R. L., & Bartholomew, E. R. (2001). The Leap Second: Its History and Possible Future. Metrologia, 38, 509529.CrossRefGoogle Scholar
Panfilo, G., Harmegnies, A., & Tisserand, L. (2012). A New Prediction Algorithm for the Generation of International Atomic Time. Metrologia, 49, 4956.CrossRefGoogle Scholar
Panfilo, G., Harmegnies, A., & Tisserand, L. (2014). A New Weighting Procedure for UTC. Metrologia, 51, 285292.CrossRefGoogle Scholar
Petit, G. (2000). Use of Primary Frequency Standards for Estimating the Duration of the Scale Unit of TAI. 31st Annual Precise Time and Time Interval (PTTI) Meeting, 297304.
Petit, G. (2010). Atomic Time Scales TAI and TT (BIPM): Present Performances and Prospects. Highlights of Astronomy, 15, XXVIIth IAU General Assembly, 220221.Google Scholar
Petit, G. & Arias, E. F. (2015). Long Term Stability of Atomic Time Scales. Highlights of Astronomy, 16, 209210.Google Scholar
Quinn, T. J. (1997). News from the BIPM. Metrologia, 34, 187194.CrossRefGoogle Scholar
Tavella, P. & Thomas, C. (1991). Comparative Study of Time Scale Algorithms. Metrologia, 28, 5763.CrossRefGoogle Scholar
Terrien, J. (1970). News from the BIPM. Metrologia, 7, 4344.CrossRefGoogle Scholar
Terrien, J. (1971). News from the BIPM. Metrologia, 8, 3236.CrossRefGoogle Scholar
Terrien, J. (1975). News from the BIPM. Metrologia, 11, 179183.CrossRefGoogle Scholar
Thomas, C. & Azoubib, J. (1996). TAI Computation: Study of an Alternative Choice for Implementing an Upper Limit of Clock Weights. Metrologia, 33, 227240.CrossRefGoogle Scholar
Time Service Notice No. 6 (1959, January 1). Washington, DC: US Naval Observatory.
Trans. Int. Astron. Union (1962), Vol. XI A, Reports on Astronomy. Edited by Sadler, D. H.. New York, NY: Academic Press, 362363.Google Scholar
Trans. Int. Astron. Union (1991), Vol. XXI B, Reports on Astronomy. Edited by McNally, D.. New York, NY: Academic Press, 362363.Google Scholar

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