New Satellite System Will Use GPS Signals To Track Hurricanes,Climate Change, and Space Weather (Forwarded)

National Center for Atmospheric Research
Boulder, Colorado

Contacts:

For Journalists:

Anatta, head of Media Relations
303-497-8604

Richard Anthes, UCAR President
303-497-1652

William Kuo, UCAR COSMIC Program Office
303-497-8910

Cheryl Dybas, NSF Public Affairs
703-292-7734

UCAR Communications:

Yvonne Mondragon, General inquiries
303-497-8601

Nita Razo, Head of Visual Services
303-497-8606

April 12, 2006

New Satellite System Will Use GPS Signals To Track Hurricanes, Climate
Change, and Space Weather

Innovative U.S.-Taiwan Satellite Constellation To Be Launched Friday

BOULDER -- A globe-spanning constellation of six satellites expected to
improve weather forecasts, monitor climate change, and enhance space
weather research will head into orbit on April 14. A Minotaur rocket is
scheduled to launch the array at 5:10 p.m. Pacific Daylight Time from
Vandenberg Air Force Base. As with any launch, delays are possible.

The low-orbiting satellites will be the first to provide atmospheric data
daily in real time over thousands of points on Earth for both research and
operational weather forecasting by measuring the bending of radio signals
from the U.S. Global Positioning System (GPS) as the signals pass through
Earth's atmosphere.

Called COSMIC (Constellation Observing System for Meteorology, Ionosphere
and Climate) in the United States and FORMOSAT-3 in Taiwan, the $100
million satellite network is the product of an agreement between the
American Institute in Taiwan and the Taipei Economic and Cultural
Representative Office in the United States. The array is based on a system
design provided by the University Corporation for Atmospheric Research
(UCAR).

Temperature and water vapor profiles derived from the GPS data will help
meteorologists observe, research, and forecast hurricanes, typhoons, and
other storm patterns over the oceans and improve many areas of weather
prediction. The stability, consistency, and accuracy of the measurements
should be a boon to scientists quantifying long-term climate change
trends.

COSMIC's measurements of electron density in the ionosphere are expected
to improve analysis and forecasting of space weather, including
geomagnetic storms that can interrupt sensitive satellite and
communications systems and affect power grids on the ground.

COSMIC relies on a technology known as radio occultation. Just as the
water molecules in a glass change the path of visible light waves so that
a pencil appears bent, molecules in the air bend GPS radio signals as they
pass through (are occulted by) the atmosphere. By measuring the amount of
this bending, scientists can determine underlying atmospheric conditions,
such as air density, temperature, and moisture, and electron density.

"This is the first time the technique of radio occultation has been used
on a large scale in real time to provide nearly continuous measurements of
worldwide atmospheric conditions at all altitudes," says William Kuo,
director of the UCAR COSMIC office.

While several single-satellite systems have used GPS signals
experimentally over the past decade, COSMIC's unique six-satellite array
is the first to provide the high-density global coverage required for both
research and operational forecasting. Its radio occultation technique
leverages significant investments by the United States, Europe, and Russia
in the Global Navigation Satellite Systems.

"Centers around the world will have access to this new information for
both research and operational forecasting," says UCAR president Richard
Anthes. "User-friendly versions of the data will enable those with less
sophisticated systems to benefit as well," he adds.

Orbiting at an altitude of 500 miles (800 kilometers), COSMIC satellites
will take approximately 2,500 measurements every 24 hours in a nearly
uniform distribution around the globe. The system will provide novel and
independent data over vast stretches of the oceans where there are no
weather balloon observations. The data's high vertical resolution will
complement the high horizontal resolution of other weather satellite
measurements.

"COSMIC/FORMOSAT-3 scientists and engineers have built a system that
cleverly measures the atmospheric bending of radio signals from the U.S.
Global Positioning System (GPS) and then converts these measurements into
a remarkably precise worldwide set of weather, climate, and space weather
data," says NSF program manager Jay Fein. "This new information will have
a tremendous impact on geosciences research and operational weather
prediction and will be an important contribution to the Global Earth
Observation System of Systems, a program led by the National Oceanic and
Atmospheric Administration."

Because radio signals pierce thick cloud cover and precipitation, weather
conditions will not interfere with data gathering, as is often the case
with remote sensing platforms. The satellites will not need to be
recalibrated and the instruments' accuracy and sensitivity will not drift
during the five-year mission -- common problems with Earth-observing
satellites over their lifetime. The data will be available to researchers
and forecasters within a few hours of the observations, making them a
potential boon to everyday forecast operations.

"The COSMIC mission would not have been possible without the broad support
of U.S. sponsors and the partnership with Taiwan," says Fein.

Taiwan's National Science Council and National Space Organization provided
over $80 million for the system. The U.S. National Science Foundation,
lead agency for COSMIC science activities, and its partners provided the
rest of the support. Major partners include NASA, NOAA, the U.S. Air Force
Space Test Program, the Office of Naval Research, and the Department of
Defense Space and Missile Systems Center's Rocket Systems Launch Program
of the U.S. Air Force, which also provided logistical support. Orbital
Sciences Corporation designed the spacecraft. NASA's Jet Propulsion
Laboratory designed and produced the prototype high-performance GPS
science receiver. Broad Reach Engineering built the receivers for the
satellite constellation. The Naval Research Laboratory designed and built
the ionospheric sensors. The rest of the constellation was built and
tested in Taiwan.

Related sites on the World Wide Web:

* Launch updates
http://www.cosmic.ucar.edu/launch
* COSMIC Visuals Gallery (stills and animations, print and broadcast
quality)
http://www.ucar.edu/news/releases/20...cvisuals.shtml
* COSMIC fact sheet
https://www.ucar.edu/news/releases/2...micfacts.shtml
* COSMIC home page
http://www.cosmic.ucar.edu/