United States Naval Observatory
High Quality Content by WIKIPEDIA articles! The United States Naval Observatory (USNO) is one of the oldest scientific agencies in the United States, with a primary mission to produce Positioning, Navigation, and Timing (PNT) for the U.S. Navy and the U.S. Department of Defense. Located in Northwest Washington, D.C., it is one of the pre-1900 astronomical observatories located in an urban area; at the time of its construction, it was far from the light pollution thrown off by the (then-smaller) city center. Today, the observatory`s primary observational work is done at the U.S. Navy`s higher elevation United States Naval Observatory, Flagstaff Station (NOFS) near Flagstaff, Arizona. USNO also has an "Alternate Master Clock" site in...
ISBN: 978-5-5087-3324-7