Height Reference Systems
- The German height reference system
- The European height reference system
- Determination of the height reference surface of Germany
- GCG2011 - German Combined QuasiGeoid 2011
GCG2011 - German Combined QuasiGeoid 2011
The Federal Agency for Cartography and Geodesy (BKG) and the Institut für Erdmessung of Leibniz University Hannover (IfE) have developed this new model of the height reference surface of Germany (GCG2011 ) in cooperation with the Arbeitsgemeinschaft der Vermessungsverwaltungen der Länder der Bundesrepublik Deutschland - AdV (Working Committee of the Surveying Authorities of the States of the Federal Republic of Germany). It represents the actual height reference surface of the AdV in Germany. The model GCG2011 succeeds the model GCG2005 published in 2005. New detailed measurements of the gravitational force of the earth provided by the AdV, improved digital terrain models and more recent global earth gravity field models form the basis of the computations. For the first time, the new model includes the whole area of Germany's Exclusive Economic Zone (EEZ) of the North Sea, which means the so-called 200 sea-mile-zone, thus providing a uniform solution that comprises the whole territory of the Federal Republic of Germany.
The GCG2011 is compatible with the ETRS89 reference system used by the Satellite Positioning Service of the Länder (SAPOS®) as well as with the official DHHN92 height system. The physical heights in the DHHN92 that are used in practice can therefore be computed by means of the GCG2011 directly from the ellipsoidal heights determined with SAPOS®:
HDHHN92 = hETRS89 – ζGCG2011
The GCG2011 allows an accuracy of this transformation of about 1 - 2 cm in lowland, 3 - 4 cm in high mountains and 4 - 10 cm in marine areas.
The quasigeoid can be obtained via the Online Shop of the Servicecenter (Online Shop > Digital spatial data of Germany > Product selection > Geodetic base data > Quasigeoid) or via the Geodata Distribution (Products > Geodata).
You can choose between a quasigeoid model for the whole territory of Germany or, optionally for five sub-regions.
- Brochure for Quasigeoid (Quasigeoid (pdf 497-KB))
- Documentation Quasigeoid 2011 (pdf 900-KB)
in the Servicecenter of the BKG