The Proceedings of IAU S248 reflect the state-of-the-art in the field of astrometry, summarizing the scientific achievements at the tenth anniversary of the Hipparcos and Tycho Catalogue release. It shows the latest achievements in ground-based astrometry and details the progress of second-generation astrometric satellites. Currently, the highest accuracies at a micro-arc-second level are reached by interferometric techniques, especially at radio wavelengths. Establishing and maintaining the celestial reference frame at this level, within a relativistic framework, has been identified as one of astrometry's main tasks. The era of large surveys and virtual observatories brings inevitable changes to the role of astrometry in astronomy. For instance, galactic structure and evolution can be fully understood only by combining astrometric and astrophysical parameters. Finally, due attention is given to astrometric education in astronomy curricula for the twenty-first century. These Proceedings convincingly demonstrate the ever growing role played by astrometry in understanding the Universe.
Preface; Organising committee; Conference participants; Address by the local organising committee C. Huang; Session 1. Hipparcos Catalogue Erik Hog; Session 2. Highlights of optical astrometry Erik H. Hog and Francois Mignard; Session 3. Astrometry with radio interferometers Edward B. Fomalont; Session 4. Space astrometry: status and the future Alexandre H. Andrei; Session 5. Celestial reference frames at multi-wavelengths Dafydd W. Evans; Session 6. Towards reference frame at the micro-arcsecond level Dafydd W. Evans and Toshio Fukushima; Session 7. Stellar parameters and Galactic structure & evolution Imants Platais and Catherine Turon; Session 8. Astrometric education and outreach Catherine Turon; Session 9. Astrometry in the age of large surveys and virtual observatories Norbert Zacharias; Closing remarks; Author index; Object index; Subject index.