The latest gravimetric quasigeoid solution (HGEO2000 - Fig. 10.) was computed at the FÖMI Satellite Geodetic Observatory in 2000. It was derived from more than 380 000 gravimetric measurements and the GPM98CR (n=720) geopotential model. The solution refers to the GRS80 geocentric ellipsoid, its estimated relative accuracy is better than 0.5 ppm. The HGEO2000 geoid solution is available in digital form on a 1.5’ by 1.5’ grid. This solution represents a major improvement both in accuracy and spatial resolution comparing to the previous versions. As the Hungarian gravimetric database has sufficient accuracy new geoid computation is only planned, when new global geopotential models will be available.

Supporting the GPS heighting activities the gravimetric quasigeoid has been combined with levelling and GPS data. The combined HGGG2000 GPS-gravimetric solution is already used in Hungary for the 3rd order densification of the vertical control network.

Fig. 10.
The HGEO2000 gravimetric quasigeoid solution. Contour interval : 0.1 m2.6. Control Networks Recent and Follow-on Activities

• Completion of the vertical network measurements by levelling and the GPS technology,
• Major actions to connect the Hungarian geodetic fundamentals to EUREF and UELN,
• Building up the Hungarian Active GPS Network,
• Maintaining and analysing the Hungarian GPS Deformation Network,
• Participating in the International GPS Service,
• Participating in the EUREF Permanent Network (EPN) activities,
• Adapting GPS technologies for application in different survey tasks,
• Using the Hungarian Gödöllő standard baseline for national and international calibrations,
• Participating in the European Vertical GPS Reference Network (EUVN) Densification project,
• Improving of the present geoid solution for GPS-heightening applications.