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Regional Models

Germany (GCG2016)

  Authors: J. Schwabe, et al.     Created: 2016    Resp: BKG  
      Status: PRIVATE    
The German Combined QuasiGeoid GCG2016 is a high-resolution hybrid model for Germany computed by the "Bundesamt für Kartographie und Geodäsie" (BKG) and the "Institut für Erdmessung" (IfE). The final solution is computed as the average of the two individual solutions from BKG and IfE. The GCG2016 model allows a direct transformation between ellipsoidal heights in the terrestrial reference system ETRS89/DREF91 (realization 2016), and normal heights in the system DHHN2016 (levelling network). The computation procedures at BKG and IfE are both based on the remove-restore technique. The input data are about 860,000 terrestrial and marine gravity disturbances, about 470 quasigeoid heights from GNSS/levelling, digital terrain models (Germany: DGM25, Europe: EuroDEM), bathymetric data of the BSH and the worldwide model GEBCO, the EIGEN6C4 global geopotential model. The BKG quasigeoid modelling is based on the adjustment of a grid of point masses. The obtained gravimetric quasigeoid is adjusted to the GNSS/levelling points by a correction surface computed by an interpolation/collocation technique. The IfE quasigeoid modelling is based on integration and collocation techniques that are applied in a two-step procedure. In the first step, the gravity and terrain data are combined with the global geopotential model by spectral combination with integral formulas. This gravimetric solution is then combined in a second step with GNSS/levelling data by collocation techniques. The overall accuracy of the final GCG2011 is estimated of the order of 1 cm (about 2 cm in the Alps and 2-6 cm in marine areas). The model is available for users at the BKG geodata center.

G. Liebsch, U. Schirmer, J. Ihde, H. Denker, J. Müller (2006). Quasigeoidbestimmung für Deutschland. Deutscher Verein für Vermessungswesen - Schriftenreihe, 49, pp. 127-146.
J. Schwabe, G. Liebsch, U. Schirmer (2016). Refined computation strategies for the new German Combined Quasigeoid GCG2016. Symposium on Geoid, Gravity and Height Systems (GGHS2016). 19-23 September 2016, Thessaloniki, Greece.