Upward Continuation of Ground Data for GOCE Calibration/Validation Purposes

authored by
K. I. Wolf, H. Denker

With the upcoming ESA satellite mission GOCE, gravitational gradients (2nd derivatives of the Earth's gravitational potential) will be measured globally, except for the polar gaps. An accuracy of a few mE (1 mE = 10-3 Eötvös, 1 E = 10-9s-2) is required to derive, in combination with satelliteto-satellite tracking (SST) measurements, a global geopotential model up to about spherical harmonic degree 200 with an accuracy of 1... 2 cm in terms of geoid undulations and 1 mgal for gravity anomalies, respectively. To meet these requirements, the gradiometer will be calibrated and validated internally as well as externally. One strategy for an external calibration or validation includes the use of ground data upward continued to satellite altitude. This strategy can only be applied regionally, because sufficiently accurate ground data are only available for selected areas. In this study, gravity anomalies over Europe are upward continued to gravitational gradients at GOCE altitude. The computations are done with synthetic data in a closed-loop simulation. Two upward continuation methods are considered, namely least-squares collocation and integral formulas based on the spectral combination technique. Both methods are described and the results are compared numerically with the ground-truth data.

Institute of Geodesy
Conference contribution
No. of pages
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Computers in Earth Sciences, Geophysics
Electronic version(s)
https://doi.org/10.1007/3-540-26932-0_11 (Access: Unknown)

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