- 1Federal Agency for Cartography and Geodesy (BKG), Gravimetry Metrology, Leipzig, Germany
- 2Research Institute of Geodesy, Topography and Cartography, Zdiby, Czech Republic
- 3Federal Institute of Metrology METAS, Wabern, Switzerland
- 4Institut Terre et Environnement de Strasbourg, Univ. Strasbourg/EOST, Strasbourg, France
- 5Finnish Geospatial Research Institute (FGI), National Land Survey of Finland (NLS), Helsinki, Finland
- 6Institute of Geodesy and Cartography (IGiK), Warsaw, Poland
- 7Główny Urząd Miar (GUM), Warsaw, Poland
- 8Geodetic Research Division, Lantmäteriet, Gävle, Sweden
- 9Istituto Nazionale di Ricerca Metrologica (INRIM), Torino, Italy
- 10Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Etneo (INGV - OE), Catania, Italy
- 11Agenzia Spaziale Italiana (ASI) / e-Geos s.p.a, Matera, Italy
- 12Slovak University of Technology, Bratislava, Slovakia
- 13LNE-OP / Laboratoire Temps Espace (LTE), Paris France
- 14GFZ Helmholtz Centre for Geoscience, Potsdam, Germany
- 15Delft University of Technology, Delft, Netherlands
- 16Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany
The validation of compatibility and long-term stability of absolute gravimeters is a key component for the realization of the International Terrestrial Gravity Reference Frame (ITGRF) of IAG and is relevant for metrology, in particular for the realization of the kilogram. Because a natural reference for the absolute value of gravity acceleration is not accessible, international comparisons of absolute gravimeters are well established. The gravity reference is realized based on a set of accurate absolute measurements and the functional model for their processing.
After the CCM.G-K2.2023 key comparison supplemented by additional comparison ICAG-2023 held in September 2023 at Table Mountain Geophysical Observatory (TMGO) Boulder, Colorado, USA, there was a need to distribute the gravity reference further to institutions in Europe. Therefore, the EURAMET key comparison of absolute gravimeters EURAMET.M.G-K2.2023 and additional comparison WETCAG-2024 was organized at the Geodetic Observatory Wettzell, Germany, in May and June 2024, where 15 institutions participated with 17 absolute gravimeters. The link to CCM.G-K2.2023 is provided by three gravimeters that took part in both comparisons. Additionally, deviations from the verticality and Eötvös/Coriolis accelerations during the free fall were determined for most of the gravimeters.
We present first results for the equivalence of the participating gravimeters as well as for the verticality and Eötvös effects. Further, we evaluate and discuss the stability of the reference values over decades, based on a reference function deduced from the registration of the superconducting gravimeter GWR SG030, repeated absolute gravity observations since 2010 and several regional comparisons performed at this station, in particular with the comparison EURAMET.M.G-K3 held at Wettzell in 2018.
Quantum gravimeters are represented in WETCAG-2024 with two instruments. This allows to compare the new technology with the reference established at the Wettzell station over 15 years, specifically in the context of stability of gravimeters and the upcoming realization of the ITGRF.
How to cite: Wziontek, H., Pálinkáš, V., Antokoletz, E. D., Baumann, H., Bernard, J.-D., Bilker-Koivula, M., Brachmann, E., Ciesielski, A., Contrafatto, D., Dykowski, P., Engfeldt, A., Facello, A., Gebauer, A., Greco, F., Iacovone, D., Janák, J., Konrad, J., Kostelecký, J., Lothhammer, A., Merlet, S., Messina, A., Näränen, J., Papčo, J., Prato, A., Reich, M., Reudink, R., and Rothleitner, C.: First results from the comparison of absolute gravimeters WETCAG-2024 at the Geodetic Observatory Wettzell, Germany, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4113, https://doi.org/10.5194/egusphere-egu25-4113, 2025.
