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Regional Models

Nordic and Baltic Region (NKG96)


  Authors: R. Forsberg, J. Kaminskis, D. Solheim     Created: 1996    Resp: R. Forsberg  
      Status: PUBLIC    

Description:
The NKG96 gravimetric quasigeoid model for the Nordic-Baltic countries has been developed by the Nordic Geodetic Commission. It extends from 53°N to 73°N and from 1°E to 33°E with a grid spacing of 1.5'x3.0'. With respect to the previous NKG89 version, the NKG gravity database has been improved by incorporating new data from Norway and Sweden (geological survey data and offshore data), from the Baltic republics (point data from digitized maps and station sheets), as well as data from Eastern Germany, Poland and Russia. The NKG96 quasigeoid was computed by the remove-restore approach. The reference geopotential global model was EGM96, while the used DEM consisted of models provided the national survey agencies and the GLOBE NGDC global topography. Residual gravity anomalies are converted into residual height anomalies by a spherical FFT evaluation of the Molodensky's integral using a modified Stokes' kernel function. The resulting quasigeoid model is referred to the WGS84 ellipsoid, with a shift of -1.06 m to account for a global geoid errors and sea-surface topography. Compared to more than 300 GPS-levelling points across the region, the NKG96 model shows a fit at the level of 10 cm.

References:
R. Forsberg, J. Kaminskis, D. Solheim (1997). Geoid for the Nordic and Baltic Region from Gravimetry and Satellite Altimetry. In: J. Segawa, H. Fujimoto, S. Okubo (eds.), Gravity, Geoid and Marine geodesy, IAG Symposia Series, vol. 117, pp. 540-547, Springer Verlag.

Nordic and Baltic Region