The current status and future developments of highly accurate, dense, astrometric surveys on the International Celestial Reference System (ICRS) are discussed. The U.S. Naval Observatory CCD Astrograph Catalog (UCAC) project is an ongoing, observational program aiming at a global sky coverage with 20 to 70 mas positional accuracy for the 10 to 16 mag range. This program extends the reference star density by a factor of about 30 over the Tycho-2 catalog, with about 10 times higher positional accuracy than the GSC I. The second UCAC release fall 2002) gives positions and proper motions for stars between -90 and about +40 degrees declination. The first release and unpublished updates have been supporting the Sloan Digital Sky Survey, 2MASS, the minor planet community, and SOAR. The next step, a 1-meter class, dedicated, robotic, wide-field, astrometric instrument is already designed (10k by 10k single CCD) and a global sky catalog to 20th magnitude could be observed in only 2 years with 10 mas accurate positions in the magnitude range between 15 to 18.
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