Geophysical monitoring: Seismic sensors, seismic data acquisitions instruments and techniques, how to project and realize a volcanic seismic network, seismic analyses for monitoring and surveillance on active volcanoes, measuring ground deformation on volcanoes with millimeter-level accuracy geodetic measurements using Global Navigation and Satellite Systems (GNSS) and interferometric analysis of synthetic aperture radar satellite images (InSAR), as well as other techniques.