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Rothacher et al. 1999
Rothacher, M., Beutler, G., Herring, T.A. and Weber, R. (1999). Estimation of nutation using the Global Positioning System. Journal of Geophysical Research 104: doi: 10.1029/1998JB900078. issn: 0148-0227.

In the past the estimation of corrections to nutation models was uniquely reserved to very long baseline interferometry (VLBI) and lunar laser ranging (LLR) data processing. Although satellite space-geodetic measurements have been used to determine UT1-UTC rates (or length of day) for many years now, the estimation of nutation rates was not performed. There is no fundamental difference, however, between the estimation of rates in UT1-UTC and nutation rates in obliquity and longitude from satellite data. A simple variance-covariance analysis shows that significant contributions to nutation by the Global Positioning System (GPS) are possible for periods below about 16 days. Since March 1994, daily nutation rates have been computed at the Center for Orbit Determination Europe using the data collected by the global GPS network. The series of nutation rates now covers 3.5 years. It is used to compute corrections for a set of 34 nutation periods between 4 and 16 days. The formal uncertainties of the estimated nutation coefficients in obliquity Δ&egr; and longitude Δ&psgr; sin &egr;0 grow linearly with period from several microarcseconds (μas) at periods of a few days to about 30 μas at periods of 16 days. The comparison of the GPS-derived coefficients with the International Earth Rotation Service 1996 nutation model shows an overall agreement of 10μas (median). The GPS results are also in very good agreement with the most recent model by Souchay and Kinoshita (1997.2), better than most of the VLBI and LLR results reported in the literature. GPS thus allows, although limited to high frequencies because of the satellite orbits involved, an independent check of the validity of theoretical nutation models and of results obtained from VLBI and LLR. ¿ 1999 American Geophysical Union

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Abstract

Keywords
Geodesy and Gravity, Rotational variations, Geodesy and Gravity, Diurnal and subdiurnal rotational variations, Geodesy and Gravity, Reference systems
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
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