Astrophysics (Index)About


(United States Naval Observatory)
(observatory obtaining astronomical data for Naval use)

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.

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:

Further reading:
USNOUSNO 689star parallax list
USNO-AUSNO-A2.0 0825-18396733astrometric catalog edition
USNO-BUSNO-B1.0 1047-0021596astrometric catalog edition

Referenced by pages:
Astrographic Catalog (AC)
plate measuring machine (APM)
astronomical catalog
double star designation
Navy Precision Optical Interferometer (NPOI)
photographic zenith tube (PZT)
USNO CCD Astrograph Catalog (UCAC)
USNO Twin Astrograph
Washington Double Star Catalog (WDS)
XZ Catalog of Zodiacal Stars (XZ)