Geodetic networks form the basis for official surveying and thus georeferenced data. They are updated as required at intervals not only due to the tectonical point movements, but also by technical and scientific developments. Within the context of the renewal work of the German Main Height Network, GNSS measurements were carried out in 2008 on 250 stations of the geodetic basic network. For the processing of data, the data evaluation centers of the Federal Agency for Cartography and Geodesy in Frankfurt am Main and the Lower Saxonian State Office for Geoinformation and Land Survey in Hannover were responsible. The primary goal of the processing of the GNSS data was the determination of 3D Cartesian coordinates in the IGS05 with an accuracy of less than 2 mm in location and 5 mm in height.