Gravity Reference Systems

• Introduction
• Gravimeter
• German Gravity Reference Systems
• European Gravity Reference Systems
• Global Gravity Reference Systems

Global gravity reference system

International gravimeter comparisons

By participating in the international comparison campaigns at the Bureau International des Poids et Mesures (BIPM) in Sèvres, France, the connection to the International Gravity Reference System was established. Germany joined the international Meter Convention in 1875. With comparative measurements of the absolute gravimeters the connection to the international system of Units (SI - Système International d'Unités) was realized, which was introduced by the 11th General Conference on Weights and Measures in 1960. Since 1994, BKG has regularly participated with its absolute gravimeter FGS5-101 in the international comparisons of absolute gravimeters.

Regional reference stations for absolute gravimeters

Additionally to the international comparisons of absolute gravimeters, the BKG also participates in regional comparisons within Europe. The gravimeter stations in Wettzell and Bad Homburg were developed to gravity comparison sites. The sites offer the possibility of accurate comparative measurements of absolute gravimeters by the combination of the absolute gravity measurements with the continuous registrations of the Superconducting Gravimeters and the reliability of the comparisons can further be improved.

AGrav – International Absolute Gravity Database

By establishing an International Absolute Gravity Database the BKG supports the international cooperation in the field of absolute gravity measurements and the establishment of a transparent International Gravity Reference System. The database is operated in close cooperation with the BGI (Bureau Gravimetrique International), the International Gravimetric Bureau in Toulouse (France) and thus is a service of the IAG and the International Gravity Field Service. It is maintained in identical manner at both institutions and is mirrored to each other (AGrav Database at the BKG).

GGP – Global Geodynamics Project

Through the observation series of the four Superconducting Gravimeters of the BKG located at Wettzell, Bad Homburg, Medicina (Italy), and Concepcion (Chile) BKG contributes to the international service of the "Global Geodynamics Project GGP" (Website of the GGP). The measuring data of all stations are checked by routine operation, preprocessed and then entered into the GGP database as raw data and corrected datasets.