3 Evaluation of EGM 2008 and EIGEN-6C3stat

The global combined high-resolution gravity field models EGM 2008 and EIGEN-6C3stat are compared by means of gravity anomalies and the radial component of the Marussi tensor. The role of the GOCE gradiometry data is detected. GNSS/leveling provides independent data source to evaluate any gravity field model. We apply such data to test EGM 2008 (without GOCE measurements) and EIGEN-6C3stat (already with them). The GNSS/leveling data set is dense (1024 points) and precise (ellipsoidal height error below 2 cm) but is available only over the territory of the Czech Republic with this density; this test has in turn a limited validity. The RMS of height differences between GNSS/leveling and EGM 2008 or GNSS/leveling and EIGEN-6C3stat is 3.3 cm or 4.1cm, respectively