Validation of marine geoid models in the North Aegean Sea using satellite altimetry, marine GPS data and astrogeodetic measurements

Abstract

A dedicated measuring campaign for geoid determination has been carried out in the North Aegean Sea, Greece, in May 2005. It was realized in the frame of a joint project between the Geodesy and Geodynamics Laboratory (GGL) of ETH Zurich, and the Department of Geodesy and Surveying of the Aristotle University of Thessaloniki. The measurement area is part of the North Aegean Trough (NAT), which forms a continuation of the seismically active North Anatolian Fault Zone. Different methods for geoid determination have been applied, including astro-geodetic observations with the new Zenith Camera DIADEM in order to determine highly-precise Deflections of the Vertical (DoV), as well as GPS boat and buoy measurements to provide Sea Surface Heights (SSH). The data gathered during the campaign were compared to existing local gravimetric and altimetric geoid models. They helped to detect long wavelength errors in the gravimetric geoid model, which are mainly due to existing data gaps in the marine area.