GEOID+ - Improved Austrian Geoid Solution Combining Terrestrial and Satellite Gravity Data

The main objective of the project GEOID+ is the computation of an improved geoid model for the Austrian territory, as acombined solution from terrestrial gravity field data and satellite-related data from the dedicated gravity field missions GRACE and GOCE, which shall stabilize the solution in the long to medium wavelength domain.

Short Description

Compared to the currently available Austrian geoid model, which was computed in the frame of the ASAP Phase 3 project "The Austrian Geoid 2007 (GEOnAUT)", several enhancements provided new, validated and more accurate terrestrial input data, the incorporation of a global gravity field model based on GOCE data, methodological improvements in the computation process, as well as the opportunity of an independent validation on the basis of the European geoid model.

The precise knowledge of the geoid, representing a physical reference surface and reference level for height systems, is required and applied in civil engineering projects, tele- communication and telematics applications, as well as numerous geoscientific applications. The height determination by the combination of GPS observations and geoid information can replace the elaborate and expensive work of spirit levelling. Also the unification and validation of the national levelling network takes benefit from a high-precision geoid.

Nowadays, the availability of high-accuracy global satellite gravity models enables to make the local geoid model consistent, also concerning the absolute level, with a global reference frame. The availability of high accuracy global gravity data from satellite missions produced the need to upgrade the formerly used standard processing strategies. Correspondingly, in the frame of this project sophisticated and innovative methods of numerical and computational mathematics shall be investigated and applied to attain this goal.

Project Partners


Graz University of Technology, Institute of Navigation and Satellite Geodesy - Prof. Norbert Kühtreiber


  • Graz University of Technology, Institute of Computational Mathematics - Prof. Olaf Steinbach
  • Approximation of the Federal Office of Metrology and Surveying - Norbert Höggerl

Contact Address

Graz University of Technology - Institute of Navigation and Satellite Geodesy
Prof. Norbert Kühtreiber
Steyrergasse 30
A-8010 Graz
Tel.: +43 (316) 873 6352