EGU General Assembly 2022
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the Creative Commons Attribution 4.0 License.

WET-CAG2021: An international comparison of absolute gravimeters for the realization of the International Gravity Reference System

Axel Rülke1, Reinhard Falk1, Andreas Engfeldt2, Julian Glässel1, Andreas Hellerschmied3, Domenico Iacovone4, Jakub Kostelecký5, Vojtech Pálinkáš5, Marvin Reich6, Ludger Timmen7, Christian Ullrich3, Alessandro Valluzzi4, Hartmut Wziontek1, and Barbara Zehetmaier3
Axel Rülke et al.
  • 1Federal Agency for Cartography and Geodesy, Leipzig and Frankfurt am Main, Germany
  • 2Geodetic Research Division, Lantmäteriet, Gävle, Sweden
  • 3Federal Office of Metrology and Surveying, Vienna, Austria
  • 4ASI / e-Geos s.p.a, Matera, Italy
  • 5Research Institute of Geodesy, Topography and Cartography, Geodetic Observatory Pecný, Ondřejov, Czech Republic
  • 6GFZ German Research Centre for Geoscience, Potsdam, Germany
  • 7Institute of Geodesy, Leibniz University Hannover, Hannover, Germany

Geodetic observations on Earth accurate to better than a part per billion require a common reference for the same precision as described in the goals of the Global Geodetic Observing System. The International Gravity Reference System (IGRS) is proposed as a new reference for terrestrial gravity observations (Wziontek et al. 2021).

The International Gravity Reference Frame (IGRF) as the realization of IGRS is represented by absolute gravity measurements traceable to the SI. Due to the lack of a natural reference, absolute gravimeters need to be compared and the gravity reference is realized based on a set of measurements by a group of absolute gravimeters and the functional model for their processing.

We present the international comparison of absolute gravimeters WET-CAG2021 hosted at the Geodetic Observatory Wettzell in autumn 2021. This comparison is classified as an additional comparison following the strategy paper of the Consultative Committee for Mass and related quantities (CCM) and IAG. Seven FG5/X absolute gravimeters and two AQG quantum gravimeters have observed up to four individual piers over a period of twelve weeks. The individual observation epochs are connected by recordings of the continuously operating superconducting gravimeter GWR OSG 030 in the same laboratory.

We show the procedure of data analysis following Pálinkáš et al. (2021) and discuss the results also with respect to the latest regional metrological EURAMET comparison 2018 at the same location.


Marti, U., Richard, P., Germak, A., Vitushkin, L., Pálinkáš, V., Wilmes, H.: CCM-IAG Strategy for Metrology in Absolute Gravimetry, 11 March 2014

Pálinkáš, V., Wziontek, H., Vaľko, M. et al.: Evaluation of comparisons of absolute gravimeters using correlated quantities: reprocessing and analyses of recent comparisons. J Geod 95, 21 (2021).

Wziontek, H., Bonvalot, S., Falk, R. et al.: Status of the International Gravity Reference System and Frame. J Geod 95, 7 (2021).

How to cite: Rülke, A., Falk, R., Engfeldt, A., Glässel, J., Hellerschmied, A., Iacovone, D., Kostelecký, J., Pálinkáš, V., Reich, M., Timmen, L., Ullrich, C., Valluzzi, A., Wziontek, H., and Zehetmaier, B.: WET-CAG2021: An international comparison of absolute gravimeters for the realization of the International Gravity Reference System, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2964,, 2022.