Notice Advisory to NAVSTAR Users
Encyclopedia
A notice advisory to NAVSTAR
users, or NANU, is a message issued jointly by the United States Coast Guard
and the GPS Operations Center at Schriever Air Force Base
in Colorado. NANUs provide updates on the general health of individual satellites in the GPS constellation
. NANUs are typically issued approximately three days prior to a change in the operation of a GPS satellite, such as a change in orbit or scheduled on-board equipment maintenance.
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
users, or NANU, is a message issued jointly by the United States Coast Guard
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...
and the GPS Operations Center at Schriever Air Force Base
Schriever Air Force Base
Schriever Air Force Base is a base of the United States Air Force located approximately 10 miles east of Peterson AFB near Colorado Springs in El Paso County, Colorado, United States.-Overview:...
in Colorado. NANUs provide updates on the general health of individual satellites in the GPS constellation
Satellite constellation
A group of artificial satellites working in concert is known as a satellite constellation. Such a constellation can be considered to be a number of satellites with coordinated ground coverage, operating together under shared control, synchronised so that they overlap well in coverage and...
. NANUs are typically issued approximately three days prior to a change in the operation of a GPS satellite, such as a change in orbit or scheduled on-board equipment maintenance.