| The IVS (International VLBI Service for Geodesy and Astrometry) was established in 1999 under the IAG and IAU. Its objectives include providing a service to support geodetic, geophysical, and astrometric research and operational activities and integrating VLBI (very long baseline interferometry) into a global Earth observing system. The IVS data set extends from 1979 and provides long-term information relevant for the International Terrestrial Reference Frame, Earth orientation variation in the Earth-fixed and inertial frames, the International Celestial Reference Frame, and meteorological parameters. The IVS network now comprises ~40 stations worldwide with 24-hr observing sessions several times per week and 1-hr sessions for UT1 every day. A major upgrade of VLBI data acquisition capability termed VLBI 2010 has begun. The progress, products and prospects of the IVS and VLBI, how they apply to topics of geophysical and geodetic interest, and how they support the IERS (International Earth Rotation and Reference Systems Service) and GGOS (Global Geodetic Observing System) will be described. |