Vassilis Sakkas (Ph.D.) is an exploration geophysicist with twenty years of experience in field operations and R&D with an emphasis on processing and interpretation of multiple geophysical (electromagnetic, magnetic, gravity, seismic) data to investigate the Earth’s interior. They have extensive experience in collecting, processing and interpretation of geodetic (GNSS) and interferometric data; joint interpretation and modeling of GNSS and interferometric data for ground deformation monitoring due to tectonic, seismic, volcanic or man-made (water/oil extraction) reasons. They are the person in charge of the permanent GNSS network of NKUA and an expert in the processing of GNSS data using Bernese software and interferometric analysis using open-source s/w.