Gravity Reference Systems

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

European Gravity Reference System

In connection with Europe’s political and economic rapprochement gravimetric data hitherto rated as secret have now become freely available also in Central and Eastern Europe. However, the differences existing between the individual gravity reference systems in these countries are so large that both the geoid models and the national height reference system could be decisively influenced by these differences. By means of absolute gravity measurements performed with five instruments at 17 stations located in 12 countries, a uniform gravity standard was introduced. Institutions from 12 countries were involved in the UNIGRACE - Unification of Gravity Systems in Central Europe - project, which was supported by the European Commission.

Within the project, a close cooperation between the countries having absolute gravimeters at their disposal (Germany, Finland, France, Austria, and Poland) and the countries with relative gravimeters (Bulgaria, Czech Republic, Hungary, Italy, Romania, Slovakia, Slovenia, Croatia) was achieved concerning the selection and preparation of the reference stations, the performance of the measuring campaigns as well as the connection to the national gravimetric networks. The stations in the countries involved were selected in such a way that in each country at least one station is located in a geologically stable region. Countries having access to the sea coast got another station in the proximity of a sea gauge. From this a total number of 17 stations resulted the gravity values of which were determined absolutely.

Absolute gravimeter stations in the UNIGRACE project - status 2000 (click to enlarge)