Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-23T14:30:46.410Z Has data issue: false hasContentIssue false
  • English
  • Français

A non-rotating origin on the instantaneous equator

Published online by Cambridge University Press:  03 August 2017

N. Capitaine  and
B. Guinot
N. Capitaine
Affiliation:
Observatoire de Paris (UA 1125 du CNRS), 61 Avenue de l'Observatoire, 75014-Paris, FRANCE
B. Guinot
Affiliation:
Bureau International des Poids et Mesures, Pavillon de Breteuil, 92310-Sèvres, FRANCE

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In order to give an exact and clear description of the angle of rotation of the Earth, we propose to use, as the reference point in space, a “non-rotating origin” (Guinot 1979) such that its hour angle, reckoned from the origin of the longitudes (or “non-rotating origin” in the Earth), represents strictly the specific rotation of the Earth. The position of this origin on the instantaneous equator depends only on the trajectory of the pole of rotation. We show that the estimation of the deduced angle of rotation is not critically affected by the precision with which this trajectory is known. We give therefore the formulae to obtain the non-rotating origin, at any date t, from a chosen fixed reference, and we propose a definition of the Universal Time which will remain valid, even if the adopted model for the precession and the nutation is revised. We show that the use of the non-rotating origin also simplifies the transformation of coordinates between the terrestrial and celestial reference systems.

Type
I. Celestial Reference Systems
Information
Symposium - International Astronomical Union , Volume 128: Earth's Rotation and Reference Frames for Geodesy and Geodynamics , 1988 , pp. 33 - 38
Copyright
Copyright © Reidel 1988 

References

Aoki, S., Guinot, B., Kaplan, G.H., Kinoshita, H., Mc Carthy, D.D., Seidelmann, P.K., 1982, ‘The new definition of Universal Time’, Astron. Astrophys. 105, 359.Google Scholar
Aoki, S. and Kinoshita, H., 1983, ‘Note on the relation between the equinox and Guinot's non-rotating origin’, Celestial Mechanics 29, 335–360.Google Scholar
Capitaine, N., Guinot, B., Souchay, J., 1986, ‘A non-rotating origin on the instantaneous equator: definition, properties and use’, accepted for publication in Celestial Mechanics 39, 283–307.Google Scholar
Guinot, B., 1979, ‘Basic problems in the kinematics of the rotation of the Earth’ in Time and the Earth's rotation, 7–18, Mc Carthy, D.D. and Pilkington, J.D. (eds), IAU Copyright.Google Scholar
Lieske, J., Lederle, T., Fricke, W., Morando, B., 1977, ‘Expressions for precession quantities based upon the IAU (1976) system of Astronomical constants’, Astron. Astrophys. 58, 1–16.Google Scholar
Mueller, I.I., 1981, ‘Reference coordinate systems for Earth Dynamics: a preview’ in Reference coordinate systems for Earth Dynamics, ed. by Gaposchkin, E. M. and Kolaczek, B., D. Reidel Publishing company, p 1–22.Google Scholar
Seidelmann, P.K., 1982, ‘1980 Theory of nutation: the final report of IAU working group on nutation’, Celestial Mechanics 27, 79–106.Google Scholar
Xu, B.X., Ahu, S.Y., Zhang, H., 1984, ‘Discussion of meaning and definition of UT’ in Astrometric Techniques, Eichhorn, H.K. and Leacok, R.J. (eds), D. Reidel Publishing Company.Google Scholar