NOAA to Ensure Global Navigation Satellite System Accuracy (Forwarded)

NOAA
Washington, D.C.

Media Contact:
David Hall, 301-713-3066

January 3, 2008

NOAA to Ensure Global Navigation Satellite System Accuracy

NOAA will lead an international effort to pinpoint the locations of more
than 40 global positioning satellites in Earth orbit, which is vital to
ensuring the accuracy of GPS data that millions worldwide rely upon every
day for safe navigation and commerce.

NOAA personnel will compile and analyze satellite orbit data from 10
analysis centers worldwide to ensure the accuracy of GPS information. For
the next four years NOAA's National Geodetic Survey will serve as the
Analysis Center Coordinator for the International Global Navigation
Satellite Systems Service, a voluntary federation of more than 200
organizations that provide continuous global satellite-tracking data.

"For GPS receivers to provide accurate information, the precise location of
positioning satellites as they orbit the Earth must first be determined,"
said David Zilkoski, director of NOAA's National Geodetic Survey. "NOAA
looks forward to leading this international partnership to produce the
highest quality satellite position data possible."

The Global Navigation Satellite Systems, which include the U.S.-based Global
Positioning System, the Russian GLONASS system, and the upcoming European
Galileo system, are used for accurately determining the geographic position
of any point on Earth.

A GPS receiver calculates its position by measuring the time it takes a
signal to travel from the satellite to the receiver. Because the signal
travels at a known rate and the time is precisely measured using an atomic
clock, the receiver can calculate its distance from the satellite. By
repeating this process from four or more GPS satellites whose orbits are
precisely known, the GPS receiver can determine its position.

NOAA is dedicated to enhancing economic security and national safety through
the prediction and research of weather and climate-related events and
information service delivery for transportation, and by providing
environmental stewardship of our nation's coastal and marine resources.
Through the emerging Global Earth Observation System of Systems (GEOSS),
NOAA is working with its federal partners, more than 70 countries and the
European Commission to develop a global monitoring network that is as
integrated as the planet it observes, predicts and protects.