NASA Embarks on a Sweeping Airborne Expedition

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

The team will survey sites in Central America to unearth archaeological secrets and preserve biological and cultural diversity and resources. From there, they will head to South America’s Patagonia ice fields and Antarctica to conduct topographic surveys to better gauge the effect of climate change.

The group will use an all-weather imaging tool, the Airborne Synthetic Aperture Radar, developed and managed by NASA’s Jet Propulsion Laboratory in Pasadena, California. Carried aboard the NASA DC-8 laboratory, AirSar can penetrate clouds and collect data at night. Its high-resolution sensors operate at multiple wavelengths and can "see" beneath treetops and through thin sand and dry snow pack. The DC-8 is one of the NASA Airborne Sciences aircraft from the Dryden Flight Research Center at Edwards Air Force Base, California.

A Flying Laboratory: AIRSAR instrument panels are mounted aboard a modified NASA DC-8 aircraft – During data collection, the plane flies at 8 kilometers over the average terrain height at a velocity of 215 meters per second.

Much of the archaeological evidence needed to understand Pre-Columbian societies in Central America comes from features on the landscape. Difficult terrain and logistics have limited ground data collection.

AirSar is expected to detect signs of ancient civilizations hidden beneath the forest. Its images will shed insights into the way modern humans interact with their landscape, and how ancient peoples lived and what became of their civilizations.

AirSar’s potential for archaeological applications was first demonstrated, at Angkor, Cambodia, where it revealed more detailed images than those obtained from radar gathered on a previous Space Shuttle flight.

The topography image on the left (above) is a false color radar image, while the image on the right shows topography data made while AirSar was being flown in interferometric mode.

In conservation science, forested ecosystems like those in Central America cover less than 30 percent of Earth’s land area, yet contain 90 percent of all living species. Such areas serve as a large pool of terrestrial carbon, have substantial interactions with Earth’s climate and have been dramatically impacted by human activities.

AirSar will collect data over sites with the highest priorities for conservation scientists to measure the structure, biomass and carbon content of the forests, evaluate changes, and develop models and methods to mitigate impacts.

In South America and Antarctica, AirSar will collect imagery and data to help determine the contribution of Southern Hemisphere glaciers to sea level rise due to climate change. In Patagonia, researchers found this contribution had more than doubled from 1995 to 2000, compared to the previous 25 years. AirSar data will make it possible to determine whether that trend is continuing or accelerating. AirSar will also provide reliable information on ice shelf thickness to measure the contribution of the glaciers to sea level.

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