Zero-height geopotential level estimation for the homogenization and modernization of the Vertical Datum of Greece

Within the frame of the “Modernization of the Hellenic Gravity Network” project, the homogenization of the Hellenic Vertical Datum is investigated. Two study areas in northern and southern Greece were selected, where the zero-level geopotential value W_o is estimated for each area. Additionally, a combined value is also estimated using a weighted least squares adjustment of Helmert orthometric heights and surface gravity values, that were recently measured, as well as recent global geopotential models. The biases in the vertical datum between northern and southern Greece are investigated through the comparison with a global conventional value. The validation of the results can lead to valuable conclusions on the possibility of a contemporary definition of the Hellenic Vertical Datum.