UCAC and URAT: Optical Astrometric Catalog Observing Programs
Conference paper with briefing charts
NAVAL OBSERVATORY WASHINGTON DC
Pagination or Media Count:
The third USNO CCD Astrograph Catalog UCAC3 all-sky catalog was released in August 2009. The final release, UCAC4, is in preparation and will include corrections and improvements to positions and proper motions, as well as publication of intermediate data. Properties of UCAC products are presented. The USNO Robotic Astrometric Telescope URAT project uses the optics of the UCAC telescope with a new, wide-field camera to cover 28 square degrees per exposure. A new all-sky survey to R approximately 18 mag will begin in 2011 from Arizona and be continued from Chile. Neutral density spots on the single bandpass filter allow observations of bright stars. URAT will be able to directly link Hipparcos stars and extragalactic sources of the International Celestial Reference Frame ICRF. Multiple sky overlaps per year will give mean positions, proper motions and parallaxes from these CCD observations. An accuracy level of 10 mas is expected for high signal-to-noise stellar observations.