A survey of marine geoid estimation using satellite altimetry and shipborne gravity data in GavdosA survey of marine geoid estimation using satellite altimetry and shipborne gravity data in Gavdos Δημοσίευση σε Συνέδριο Conference Publication 2015-11-142002enThe possibility of improving the determination of the marine geoid is investigated in the area of the isle of Gavdos, Greece. In the frame of the GAVDOS project, the need of a new high-resolution and high-accuracy geoid model for the calibration of the satellite's (JASON-1, ENVISAT and EURO-GLOSS) altimeters and for sea level monitoring has become apparent. This is mainly due to the fact that the already avail- able solutions are determined using outdated datasets and fail to meet the wanted, cm-level, accuracy requirements. To meet our goal, multi-satellite (ERS1, GEOSAT, TOPEX/POSEIDON (T/P)) altimetry and shipborne gravity data have been used in an attempt to improve the estimation of the marine geoid. The altimetry data come from the latest releases of the satellite's Geophysical Data Records (GDRs), based on the improved JGM-3 model and the T/P orbits, while the gravity information has been derived from available marine and land databases. Altimetric, gravimetric and com- bined solutions, using the Fast Fourier Transform (FFT) based Input Output System Theory (IOST) for the efficient combination of heterogeneous data, are determined. Data from the T/P mission, known for their high precision, are used to provide an es- timate of the achievable accuracy. Geoid models from previous research works for the Mediterranean are also implemented in the validation procedures. The results show that altimetric geoid modeling with an accuracy close to 5 cm is feasible, while the satellite altimetry data contribute to an improvement of the gravimetric geoid determi- nation by 15-20 cm. http://creativecommons.org/licenses/by/4.0/27th European Geophysical Society General Assembly Cocard Marc Papafitsorou-Marti A. Geiger Alain Clive Banks Andrew Damianidis K. Drakopoulos Panos G. Exertier P. Forsberg Rene Frantzis Xenofon Φραντζης Ξενοφων Gidskehaug A. Koutroulis Eftychios Κουτρουλης Ευτυχιος Maratos A. Mavraeidopoulos Athanasios Papadopoulos Athanasios Παπαδοπουλος Αθανασιος Pavlis Erricos C. Pesec P. Spyridakis Nektarios Tziavos Ilias N. Vergos Georgios S. AIS (Ships) Automated identification systems, Marine Automatic identification systems, Marine Shipborne automatic identification systems Universal Shipborne Automatic Identification System ships automatic identification systems ais ships automated identification systems marine automatic identification systems marine shipborne automatic identification systems universal shipborne automatic identification system