MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
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Contacts: Mary Hardin, JPL, (818) 354-0344
Fred A. Brown, NASA Dryden Flight Research Center,
FOR IMMEDIATE RELEASEApril 16, 1998
NASA's FLYING LABORATORY CONDUCTS EARTH SCIENCE MISSION
NASA's airborne imaging radar system is set to its first
major campaign of 1998, a three-week series of missions involving
11 flights from April 17 through May 1 focusing on 13 imaging and
data-collection Earth science experiments.
The highly modified jetliner is one of three specialized
aircraft in NASA's Airborne Science Program based at NASA's
Dryden Flight Research Center, Edwards, CA. The DC-8 serves as a
platform for multiple experiments at altitudes up to 42,000 feet.
The current campaign centers on the remote imaging and data-
collection capabilities of the Airborne Synthetic Aperture Radar
(AIRSAR) system developed at NASA's Jet Propulsion Laboratory.
Two AIRSAR antenna systems mounted on the DC-8's left rear
fuselage, assisted by an integrated Global Positioning
System/Inertial Navigation System, allow for precision
measurement of the resulting high-resolution digital elevation
According to Chris Jennison, Dryden's mission manager for
this campaign, the primary objective of this series of flights is
to obtain data for use in topographic mapping, geologic research
"Because it produces such a wide variety of data, the
synthetic aperture radar can be used to interpret many different
environmental and natural phenomena, such as moisture content and
soil studies," he said. "We fly at a very specific altitude and a
very precise speed. By accurately measuring the time between when
a radar pulse is sent out and when it's returned to the antenna,
the radar can produce a very fine resolution image."
AIRSAR was developed more than a decade ago by JPL radar
scientists and engineers. It is an all-weather imaging device
that can penetrate clouds, forest canopies and, in dry areas,
thin sand and dry snow packs. AIRSAR sends and receives radar
waves that are sensitive to the material on Earth's surface such
as geologic features, vegetation and water content.
Experiments are being flown over mountains in the Pacific
Northwest, the Missouri River floodplain, the Gulf Coast, several
locations in the Southwest and a number of geologic sites in
California. Individual missions are being flown from McChord Air
Force Base, Tacoma, WA.; Kelly Air Force Base, San Antonio, TX;
and Dryden at Edwards Air Force Base in Southern California.
One flight over the Pacific Northwest is focused on a multi-
altitude forestry study over Oregon's Santiam Pass as well as
data collection over Blue Glacier in Washington's Olympic
"Data collection at three different altitudes allows the
study of the varying degrees of radar penetration into the forest
canopy. This will shed light on the use of interferometry to
estimate the vertical characteristics within a forest," said
Ellen O'Leary, AIRSAR science coordinator at JPL. Interferometery
is a technique that collects three-dimensional images of the
Three flights from Dryden will target AIRSAR on 11 different
geologic sites around California. These studies range from sites
of surface deformations due to earthquake activity and oil and
water extraction, to evaluation of the radar's ability to
estimate snow properties and the amount of water released during
melting. Study locations extend from the Geysers Natural Area and
the Hayward Fault in Northern California to the Santa Cruz and
Monterey Bay coastal areas, the Sierra Nevada range and the Santa
Monica and San Gabriel Mountains in the southern part of the
The AIRSAR science mission is managed by JPL, a division of
the California Institute of Technology, for NASA's Office of
Earth Sciences, Washington, DC.
NOTE TO EDITORS: Still photos and video footage are available
from the Dryden Public Affairs Office to support this release.
For photo prints or video dubs, please call (805) 258-3449.
Photos are also available on the Internet at