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.
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., 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: