The Impact of the New IAU Resolutions on ICRF Definition and Realization

  • N. CapitaineEmail author
Conference paper
Part of the International Association of Geodesy Symposia book series (IAG SYMPOSIA, volume 138)


Following the adoption of the International Celestial Reference System and Frame (ICRS and ICRF) by the IAU in 1997, several resolutions on reference systems have been passed by the IAU in 2000 and 2006 and endorsed by the IUGG in 2003 and 2007, respectively. These resolutions concern especially the transformation between the International Terrestrial Reference System (ITRS) and the Geocentric Celestial Reference System (GCRS) that is essential for realizing the ICRS from directions of extragalactic radio sources observed from the Earth by VLBI.

First, the IAU 2000 resolutions have refined the concepts and definition of the astronomical reference systems and parameters for Earth’s rotation, and adopted the IAU 2000 precession-nutation. Then, the IAU 2006 resolutions have adopted a new precession model that is consistent with dynamical theories and have addressed definition, terminology or orientation issues relative to reference systems and time scales that needed to be specified after the adoption of the IAU 2000 resolutions. These in particular provide a refined definition of the pole and the origin on the equator as well as a rigorous definition of sidereal rotation of the Earth. These also allow an accurate realization of the celestial intermediate system that replaces the classical celestial system based on the true equator and equinox of date. There was an additional IUGG 2007 resolution for the terrestrial reference system. Finally, the IAU 2009. Transactions of the IAU XXVIIB. Rio de Janeiro, Corbett I (ed) vol 6. Cambridge University Press, pp 55–70) resolutions have adopted a new system of astronomical constants – including conventional values of the IAU 2000/2006 resolutions – and adopted the Second Realization, ICRF2, of the International Celestial Reference Frame.

This paper recalls the main aspects of these recent IAU resolutions as well as their consequences on the concepts, definitions, nomenclature and models that are suitable for modern realizations of reference systems. The impact of these resolutions on the definition and realization of the International Celestial Reference Frame (ICRF) is described.


Earth rotation Reference systems Time 


  1. Brumberg V, Bretagnon P, Francou G (1992) In: Capitaine N (ed) The proceedings of the Journées Systèmes de reference spatio-temporels, Observatoire de Paris, pp 141–148Google Scholar
  2. Capitaine, N and the IAU NFA WG (2007) In: van derHucht KA (ed) Transactions of the IAU XXVIB, vol 14, pp 474–475Google Scholar
  3. Capitaine N, Guinot B, McCarthy DD (2000) Definition of the Celestial Ephemeris origin and of UT1 in the International Celestial Reference Frame. A&A 355(1), pp. 398–405Google Scholar
  4. Capitaine N, Wallace PT (2006) Precession-nutation procedures consistent with IAU 2006 resolutions. A&A 450: pp. 855–872, doi: 10.1051/0004-6361:20054550
  5. Capitaine N, Wallace PT, Chapront J (2003) Expressions for IAU 2000 precession quantities, A&A 412(2), pp. 567–586, doi: 10.1051/0004-6361:20031539
  6. IERS Conventions (2003) IERS technical note 32. In: McCarthy DD, Petit G (eds) Frankfurt am Main: Verlag des desamts für Kartographie und Geodäsie, 2004Google Scholar
  7. Fukushima T (1991) Geodesic Nutation A&A 244(1), pp. L11–L12Google Scholar
  8. Guinot B (1979) Basic Problems in the Kinematics of the Rotation of the Earth in Time and the Earth’s Rotation. In: McCarthy DD, Pilkington JD (eds) Time and the Earth’s rotation. Dordrecht D. Reidel Publishing Company, pp. 7–18Google Scholar
  9. Hilton J, Capitaine N, Chapront J et al (2006) Report of the International Astronomical Union Division I Working Group on Precession and the Ecliptic. Celest Mech Dyn Astr 94(3), pp. 351–367, doi: 10.1007/s10569-006-0001-2 CrossRefGoogle Scholar
  10. IAU (1997) In: Andersen J. (ed) Transactions of the IAU Vol. XXIII B; Kluwer Academic Publishers, ISBN  0-7923-5588-1
  11. IAU (2000) In: Rickman H. (ed) Transactions of the IAU Vol. XXIV B, ASP, ISBN  1-58381-087-0
  12. IAU (2006) In: van der Hucht KA (ed) Transactions of the IAU Vol. XXVIB, Cambridge University Press, ISBN  978-0-521-85606-5
  13. IAU (2006) NFA glossary of the IAU working group on nomenclature for fundamental astronomy.
  14. IAU (2009) In: Corbett I (ed) Transactions of the IAU XXVIIB, Cambridge University Press, ISBN 9780-521-76831-3. Cambridge University Press, pp 55–70Google Scholar
  15. IUGG (2003) IUGG Resolutions.
  16. IUGG (2007) IUGG Resolutions.
  17. Mathews PM, Herring TA, Buffett BA (2002) Modeling of nutation and precession: New nutation series for nonrigid Earth, and insights into the Earth’s Interior. J Geophys Res 107(B4). doi: 10.1029/2001JB000390
  18. Soffel M, Klioner SA, Petit et al. (2003) The IAU 2000 Resolutions for Astrometry, Celestial Mechanics, and Metrology in the Relativistic Framework: Explanatory Supplement, AJ 126, 6, pp. 2687–2706, doi: 10.1086/378162
  19. Souchay J, Loysel B, Kinoshita H, Folgueira M (1999) Corrections and new developments in rigid Earth nutation theory: III. Final tables REN-2000 including crossed-nutation and spin-orbit coupling effects. A&AS 135(1), pp. 111–131, doi: 10.1051/aas:1999446
  20. Wallace PT (1998) SOFA: Standards of Fundamental Astronomy. In: Andersen J (ed) Highlights of astronomy, vol 11A. Kluwer Academic Publishers, p. 191Google Scholar
  21. Wallace PT, Capitaine N (2006) Precession-nutation procedures consistent with IAU 2006 resolutions. A&A 459(3): pp. 981–985, doi: 10.1051/0004-6361:20065897
  22. Williams JG (1994) Contributions to the Earth’s obliquity rate, precession, and nutation. AJ 108(2): pp. 711–724, doi: 10.1086/117108

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.SYRTE, Observatoire de Paris, CNRS, UPMCParisFrance

Personalised recommendations