This report presents the evaluation results for the new Earth Gravitational Model (EGM08) that was recently released by theUS National Geospatial-Intelligence Agency, using GPS and leveled orthometric heights in the area of Greece. Detailed comparisons of geoidundu-lations obtained from the EGM08 model and other combined global geopotential models (GGMs) with GPS/leveling data have been performed in both absoluteand relative sense. The test network covers the entire part of the Hellenic mainland and it consists ofmore than 1500 benchmarks which belong to the Hellenic national triangulation network, with direct leveling tiesto the Hellenic vertical reference frame. The spatial positions ofthese bench-marks have been recently determined at cm-level accuracy (with respect to ITRF2000) during a nation-wide GPS campaign that was organized in the frame of the HEPOS project. Our results reveal that EGM08 offers a major improvement (more than 60%) for the agreement among geoidal, ellipsoidal and orthometric heights over the mainland part of Greece, compared to the performance of other combined GGMs for the same area.
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