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 other sea travel have had a need for accurate astronomical data for centuries, so such navy-related observatories are not unusual.

It 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.


Referenced by:
Astrographic Catalog (AC)
plate measuring machine (APM)
astronomical catalog
Washington Double Star Catalog (WDS)