Accurate determination and monitoring of sea-level changes are of fundamental value and crucial in understanding the ocean’s influence on our weather patterns and long-term climate changes. Satellite altimetry provides the only means for monitoring changes in sea level, unequivocally, over regional to global scales with [mm/yr] accuracy and with respect to the centre of mass of the Earth. Achievement of this level of accuracy requires a joint world and continuous effort for long-term and consistent calibration of the on-board satellite altimeters, using dedicated calibration sites. The main objective of this SOFIA project has been to upgrade such a satellite calibration infrastructure in Gavdos, Greece, but also develop new prototype scientific instruments to promote satellite quality, and reliability and extend the applications of satellite data to tectonic deformation monitoring. The Laboratory of Geodesy and Geomatics Engineering (GeoMatLab) at the Technical University of Crete in Greece operates such calibration facilities for satellite radar altimeters. Scientists initiated the project SOFIA (Enhancement of Crete's potential for a dedicated calibration facility for satellite radar altimeters and for tectonic deformation monitoring using continuously operating geodetic arrays) to improve the existing infrastructure and attract qualified personnel. With EU funds, the laboratory's infrastructure was modernised, and algorithms for satellite altimetry calibration and validation were developed. New satellite receivers were installed for the European Geostationary Navigation Overlay Service (EGNOS). Also, a prototype microwave transponder for calibrating satellite altimeters has been manufactured and put into operation under the supervision of the European Space Agency (ESA). A significant amount of the EU financial support was allocated to recruiting the experts needed to establish a permanent satellite calibration facility. Funding enabled GeoMatLab personnel to attend training events in Italy and the United States. They were also able to participate in summer schools organised by the International Association of Geodesy (IAG) and ESA. The SOFIA project has enabled GeoMatLab to forge collaborations with well-established European and international institutes. Greater international visibility for the GeoMatLab and enhanced research capability led to setting up a strategic partnership with Wuhan University, China and the installation of the first European receiver for BeiDou, the Chinese global navigation satellite system. Thanks to long-term international partnerships that have been formed, GeoMatLab is now better integrated into the European Research Area (ERA).
Satellite radar altimeters, environmental protection, earthquake risk, tectonic deformation, satellite calibration