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An a priori model for the reduction of nutation observations: KSV1994.3 nutation series

Published online by Cambridge University Press:  30 March 2016

T.A. Herring*
Affiliation:
Massachusetts Institute of Technology 77 Massachusetts Avenue, Cambridge, MA. 02139, USA.

Abstract

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We discuss the formulation of a new nutation series to be used in the reduction of modern space geodetic data. The motivation for developing such a series is to develop a nutation series that has smaller short period errors than the IAU 1980 nutation series and to provide a series that can be used with techniques such as the Global Positioning System (GPS) that have sensitivity to nutations but can directly separate the effects of nutations from errors in the dynamical force models that effect the satellite orbits. A modern nutation series should allow the errors in the force models for GPS to be better understood. The series is constructed by convolving the Kinoshita and Souchay rigid Earth nutation series with an Earth response function whose parameters are partly based on geophysical models of the Earth and partly estimated from a long series (1979-1993) of very long baseline interferometry (VLBI) estimates of nutation angles. Secular rates of change of the nutation angles to represent corrections to the precession constant and a secular change of the obliquity of the ecliptic are included in the theory. Time dependent amplitudes of the Free Core Nutation (FCN) that is most likely excited by variations in atmospheric pressure are included when the geophysical parameters are estimated. The complex components of the prograde annual nutation are estimated simultaneously with the geophysical parameters because of the large contribution to the nutation from the S1 atmospheric tide. The weighted root mean square (WRMS) scatter of the nutation angle estimates about this new model are 0.32 mas and the largest correction to the series when the amplitudes of the ten largest nutations are estimated is 0.17 ± 0.03 mas for the in phase component of the prograde 18.6 year nutation.

Type
II. Joint Discussions
Copyright
Copyright © Kluwer 1995

References

Chapman, S. and Lindzen, R.S. (1970) Atmospheric Tides, Reidel, Dordrecht, Holland, 200 pp.Google Scholar
de Vries, D. and Wahr, J. M (1991) The effects of the solid inner core and nonhydrostatic structure on the Earth’s forced nutations and Earth tides, J. Geophys. Res. 96, pp. 82758293.Google Scholar
Dickey, J.O., Bender, P.L., Faller, J.E., Newhall, X.X. and Ricklefs, R.L. (1991) Lunar Laser Ranging: A Continuing Legacy of the Apollo, Science 265, pp. 51715174.Google Scholar
Fukushima, T. (1991) Geodesic nutation, Astron. Astrophys. 244, pp. L11.Google Scholar
Herring, T.A., Mathews, P.M., Buffet, B.A., and Shapiro, I.I. (1991) Forced nutations of the Earth: Influence of inner core dynamics 3. Very long baseline interferometry data analysis, J. Geophys. Res. 96, pp. 82598274.Google Scholar
Herring, T.A. and Dong, D. (1994) Diurnal and semidiurnal rotational variations and tidal parameters of the Earth, J. Geophys. Res. 99, pp. 18,05118,072.Google Scholar
Kinoshita, H., and Souchay, (1990) The theory of the nutations for the rigid Earth at the second order, Celes. Mech. and Dynam. Astron. 48, pp. 187266.Google Scholar
Mathews, P.M., Buffet, B.A., Herring, T.A. and Shapiro, I.I. (1991) Forced nutations of the Earth: Influence of inner core dynamics 1. Theory, J. Geophys. Res. 96, pp. 82198243.Google Scholar
Mathews, P.M., Buffet, B.A., Herring, T.A. and Shapiro, I.I. (1991) Forced nutations of the Earth: Influence of inner core dynamics 2. Numerical results and comparisons, J. Geophys. Res. 96, pp. 82448258.Google Scholar
Sasao, T. and Wahr, J.M. (1981) An excitation mechanism for the “free core nutation,” Geophys. J. Roy, Astron. Soc. 64, pp. 729746.Google Scholar
Sovers, O.J., Jacobs, C.S. and Gross, R.S. (1993) Measuring rapid ocean tidal Earth orientation variations with very long baseline interferometry J. Geophys. Res. 98, pp. 19,95919,971.Google Scholar
Wahr, J.M. (1981) The forced nutations of an elliptical, rotating, elastic, and oceanless Earth, Geophys. J. Roy. Astron. Soc. 64, pp. 705727.Google Scholar
Wahr, J.M. and Sasao, T. (1981) A diurnal resonance in the ocean tide and the Earth’s load response due to the resonant free “core nutation,” Geophys. J. Roy. Astron. Soc. 64, pp. 747765.Google Scholar
Watkins, M.M. and Eanes, R.J. (1994) Diurnal and semidiurnal variations in Earth orientation determined from LAGEOS laser ranging, J. Geophys. Res. 99, pp. 18,07318,090.Google Scholar
Williams, J.G. (1994) Contributions to the Earth’s obliquity rate, precession, and nutation, Aston. J., in press.Google Scholar