March 3, 2004

Elvia Thompson
Headquarters, Washington
(Phone: 202/358-1696)

Alan Buis
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-0474) 

Beth Hagenauer
Dryden Flight Research Center, Edwards, Calif.
(Phone: 661/276-7960)

RELEASE: 04-078

NASA EMBARKS ON A SWEEPING AIRBORNE EXPEDITION

An international team of scientists from NASA and other research 
institutions embarked on a three-week expedition of discovery that 
will take them from the lush, dense rain forests of Central America 
to the frigid isolation of Antarctica. 

Armed with a unique radar instrument, the team will survey selected 
sites in Central America to help unearth archaeological secrets, 
preserve resources, biological and cultural diversity. Then 
scientists are off to South America's Patagonia ice fields and 
Antarctica to conduct topographic surveys of ice to better gauge the 
effect of climate change.

Despite these harsh, exotic locales, this expedition won't encounter a 
single snake or spider, and parkas are definitely not required. 
That's because the team's savvy tour guide is an all-weather imaging 
tool, the Airborne Synthetic Aperture Radar (AirSar), developed and 
managed by NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif. 
Carried aboard a NASA DC-8 laboratory, AirSar can penetrate clouds 
and also collect data at night. Its high-resolution sensors operate 
at multiple wavelengths, polarizations and in interferometric modes. 
This means they "see" beneath treetops, through thin sand, and dry 
snow pack. The sensors can produce topographic models.

Drs. Ron Blom, Eric Rignot and Sassan Saatchi of JPL are leaders of 
the campaign's terrestrial science, cryospheric, and ecology and 
conservation science teams, respectively. They left NASA's Dryden 
Flight Research Center in California on the DC-8 bound for southern 
Mexico and Central America. Rignot will continue on to Chile to 
survey Patagonian ice fields, and the Antarctic Peninsula.

Much of the archaeological evidence needed to understand Pre-Columbian 
societies in Central America comes from identifying and documenting 
features remaining on the landscape. Difficult terrain and logistics 
have limited ground-data collection. Previous remote sensing 
techniques were unable to penetrate the forest canopy. AirSar is 
expected to detect features such as fortifications, causeways, walls 
and other evidence of advanced civilizations hidden beneath the 
forest. Images will shed insight into how modern humans interact with 
their landscape, how ancient peoples lived and what became of them. 

AirSar's archaeological applications were first demonstrated at 
Angkor, Cambodia, in 1996. It provided better detail than radar 
images obtained from a previous Space Shuttle flight. In South 
America and Antarctica, AirSar will collect imagery and 
high-precision topography data to help determine the contribution of 
Southern Hemisphere glaciers to sea level rise due to climate change. 
In Patagonia, a recent study by NASA and others found the 
contribution more than doubled from 1995 to 2000 compared to the 
previous 25 years. AirSar will make it possible to determine whether 
that trend is continuing or accelerating.

Not much is known about the poorly mapped glaciers in the Antarctic 
Peninsula, an area 10 times larger than Patagonia. The area recently 
experienced rapid atmospheric warming, triggering a widespread 
retreat of floating ice shelves, reducing permanent snow cover and 
lengthening the melt season. AirSar will provide reliable information 
on ice shelf thickness to measure the contribution of the glaciers to 
sea level rise. It will also provide a precise topographic reference 
for comparison with satellite laser-altimetry data from NASA's Icesat 
satellite and previous airborne data. 

AirSar's 2004 campaign is a collaboration of many U.S. and Central 
American institutions and scientists, including NASA; the National 
Science Foundation; the Smithsonian Institute; National Geographic; 
Conservation International; the Organization of Tropical Studies; the 
Central American Commission for Environment and Development; and the 
Inter-American Development Bank.

For information about NASA and agency programs on the Internet, visit: 


http://www.nasa.gov

For information about AirSar on the Internet, visit: 

http://airsar.jpl.nasa.gov 
and 
http://www.dfrc.nasa.gov/Research<a>

	
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