Description:
DKgeoid12A is a hybrid geoid model for Denmark, covering the area 54-58°N and 7-17°E with a grid resolution of 0.01° x 0.016666°,
corresponding to about 1 km. It is an update of the DKgeoid12 model changing the underlying gravimetric geoid, which is computed by
collocation grid, followed by spherical FFT with Wong-Gore modification of the Stokes kernel. The reference field is a combination of EGM2008
and the latest GOCE model. No digital terrain models are taken into account. The NKG gravity database is used, together with airborne gravity
measurements and new gravity data for the Fehmarn Belt geoid. The resulting gravimetric geoid, which is fundamentally different from the NKG
models, is then adapted to 720 GPS/levelling observations in the Danish Vertical Datum DVR90. The resulting DKgeoid12A model has the same
accuracy in the GPS/levelling fitting as DKgeoid12 (6 mm, 1 sigma) and therefore the two models are quite similar where GPS/levelling data
are available. However, outside these areas, they are significantly different because DKgeoid12A includes new gravity data and, above all,
a better control of the long wavelengths from GOCE. Danish geoid models are developed by DTU Space, as part of the cooperation contract with
the Danish Agency for Data Supply and Efficiency (SDFE).
References:
R. Forsberg (2016). (Endnu en) ny dansk geoide
DKGEOID12A – fra tyngdedata, GOCE og GPS. Report of National Space Institute at the Technical University of Denmark, Copenhagen, Denmark (in Danish).
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