International VLBI Service for Geodesy and Astrometry (IVS)

The International VLBI Service for Geodesy and Astrometry (IVS) is a global collaboration that uses large radio telescopes linked together via precise timing to measure Earth's shape, position, and movements, as well as the positions of celestial objects. By observing distant quasars and other radio sources, IVS helps refine our understanding of Earth's rotation, orientation, and plate tectonics, supporting accurate navigation, mapping, and scientific research. This international effort ensures continuous, high-precision data critical for understanding Earth's dynamics and maintaining global positioning systems.