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Combined Analysis of Earth Orientation Parameters and Gravity Field Coefficients for Mutual Validation

authored by
A. Heiker, H. Kutterer, J. Müller

The determination of the temporal variations of the Earth orientation parameters (EOP) and spherical harmonic coefficients of the gravity field are geodetic contributions to the analysis of global geodynamic processes. As the Earth's tensor of inertia is functionally related both to the EOP via the Euler-Liouville equations and directly to the gravity field coefficients of degree 2 it allows the mutual validation of these two sets of parameters. This paper proposes a statistically founded method of combining the temporal variations of the EOP and of the gravity field coefficients of degree 2 by a leastsquares estimation based on the Gauss-Helmert model (condition equations with unknowns). Thereby statistically founded values for the unknown parameters can be derived, together with residuals for the observations, checkability and accuracy measures. The EOP and gravity field coefficients of degree 2 are introduced as observations together with correction terms such as excitation functions of atmosphere and ocean. The results of the Gauss-Helmert model computed with gravity field coefficients from GRACE and the C04 series from the International Earth Rotation and Reference Systems Service are shown in this paper. If given standard deviations are taken into account and covariances are neglected the following results are obtained: Δlod is coupled with C20 and vice versa, C21 and S21 are coupled with the polar motion, but the polar motion itself and the gravity field coefficients C22 and S22 are not checked by any other parameter.

Institute of Geodesy
Geodetic Institute
Conference contribution
No. of pages
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Computers in Earth Sciences, Geophysics
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