4 monitoring & controlling the gps, 5 gps information sources – AvMap GeoPilot II Plus User Manual

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7.3.4 monitoring & Controlling The GPS

The Global Positioning System is monitored and controlled by the U.S. Air Force, which is responsible

for updating and maintaining exact satellite position and signal data accuracy.

It is also responsible for performing maintenance on the satellites, which may require the satellite

being taken off-line. Since the system is subject to periodic updates and changes, the almanac data

broadcast by the satellites is current for a limited time — generally about 14 days.

7.3.5 GPS Information Sources

The needs of the worldwide civil GPS user community are served by the Civil GPS Information

Center (GPSIC) in Virginia. The GPSIC is operated and maintained by the U.S. Coast Guard for the

Department of Homeland Security.

Its primary function is to provide information on the Global Positioning System and satellite status

and to serve as a point of contact.

The GPSIC has general GPS literature available free upon request. The Center also maintains up-

to-date almanac data and Operational Advisory Broadcasts containing current constellation status

and planned satellite outages.

There are three ways to quickly obtain current information about the Global Positioning System

from the GPSIC:

1

. Recorded phone message at (03) 313-590

2

. WebSite: www.navcen.uscg.mil

3

. Live information at phone (03) 313-5900.

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