USNO

The USNO (United States Naval Observatory) is the USA's research facility to collect astronomical data for use by the Navy and other branches of the military. Navies (and sea travel in general) have needed accurate astronomical data for centuries and such navy-related observatories are not unusual. Astronomy continues to be relevant to navigation and location for military purposes, if nothing else, for confirming the precise position of navigation-related satellites.

The USNO has carried out extensive astrometric surveys producing catalogs (e.g., NOMAD) and also measures and collates accurate and precise data about the Earth's position, about time, about the expected positions of the Sun and Moon, and about daylight, i.e., when and where it is present over the Earth.

The USNO was established at a site in Washington, D.C., (Washington Naval Observatory, abbreviated WNO) but its sizable telescopes are now at a less-urban site (United States Naval Observatory Flagstaff Station, NOFS) near Flagstaff, Arizona, for less light pollution. Telescopes at Flagstaff:

• Kaj Strand Telescope (1.55-mm reflector).
• 1.3-meter reflector.
• 1.0-meter reflector.
• FASTT for Flagstaff Astrometric Scanning Transit Telescope - 8 inch.

Also, Lowell Observatory's Navy Precision Optical Interferometer (NPOI) is a collaboration with the USNO.