The Global Navigation Satellite System (GNSS) is an observation tool with high temporal resolution that enables monitoring of crustal deformation caused by earthquakes and volcanic activity, the dynamics of water vapor in the troposphere, and spatiotemporal variations in the ionosphere induced by solar activity and other surface phenomena.
In Japan, the Geospatial Information Authority of Japan (GSI) has operated GEONET since 1996, now comprising more than 1,300 GNSS observation stations spaced about 20-30 km apart, which has contributed significantly to advancing our understanding of a wide range of Earth science phenomena.
In recent years, rapid technological developments such as automated driving and drones have emerged. GNSS forms the foundation of the navigation technology that supports these applications. In addition to conventional metric positioning, centimeter-level real-time positioning using carrier-phase measurements is becoming widely available. Mobile network operators have begun deploying their own GNSS observation networks across Japan as reference sites, and their applications to Earth science have recently begun.
In this session, we discuss the usability and challenges of dense GNSS observation networks and explore a broad range of Earth science topics that can be addressed using dense GNSS observation data. While motivated by Japan's experience, we explicitly welcome submissions from outside Japan, including international case studies, comparative analyses, and cross-regional perspectives.

The Global Navigation Satellite System (GNSS) is an observation tool with high temporal resolution that enables monitoring of crustal deformation caused by earthquakes and volcanic activity, the dynamics of water vapor in the troposphere, and spatiotemporal variations in the ionosphere induced by solar activity and other surface phenomena.
In Japan, the Geospatial Information Authority of Japan (GSI) has operated GEONET since 1996, now comprising more than 1,300 GNSS observation stations spaced about 20-30 km apart, which has contributed significantly to advancing our understanding of a wide range of Earth science phenomena.
In recent years, rapid technological developments such as automated driving and drones have emerged. GNSS forms the foundation of the navigation technology that supports these applications. In addition to conventional metric positioning, centimeter-level real-time positioning using carrier-phase measurements is becoming widely available. Mobile network operators have begun deploying their own GNSS observation networks across Japan as reference sites, and their applications to Earth science have recently begun.
In this session, we discuss the usability and challenges of dense GNSS observation networks and explore a broad range of Earth science topics that can be addressed using dense GNSS observation data. While motivated by Japan's experience, we explicitly welcome submissions from outside Japan, including international case studies, comparative analyses, and cross-regional perspectives.