The Global Geodetic Observing System (GGOS) is an international collaboration of geodetic services and experts working together to provide geodetic data and products that serve science and society beyond the traditional task of measuring and mapping the Earth's surface. GGOS integrates ground- and space-based geodetic observations in order to monitor the Earth's time-variable shape, rotation and gravity. Changes to these characteristics are inherently related to interactions within and between the various components of the Earth system, demonstrating the importance of geodesy in monitoring the changing Earth. To advance our understanding of the underlying processes, the accuracy of geodetic measurements must be one to two levels higher than the magnitude of the changes to be detected. Examples of particularly demanding applications of geodetic measurements include mass transport across the Earth's spheres, the effects of climate change, and geohazards. This session is a forum for discussing ongoing and planned improvements to observing systems for the Earth's geometry, gravity, and rotation, particularly those that envisage the application of new methods and technologies, such as relativistic geodesy, quantum sensors, next generation lasers, PNT based on LEO satellites, etc. We also welcome general contributions on GGOS, including progress reports and plans for the next generation of geodetic observatories integrating measurements of the Earth's geometry, gravimetry, and rotation.
Sébastien Merlet