The International VLBI Service for Geodesy and Astrometry (IVS) is a service of the International Association of Geodesy (IAG), officially established in July 1999. The IVS coordinates an international network of organizations that operate or support Very Long Baseline Interferometry (VLBI) components. The IVS provides freely and openly available VLBI data and products in support of geodetic and astrometric work on reference systems, Earth science research, and operational activities.
Within the framework of the IERS, the IVS contributes to the realization and maintenance of the International Terrestrial Reference Frame (ITRF) and the International Celestial Reference Frame (ICRF), as well as to the determination of Earth Orientation Parameters (EOPs).
