NASA Gulfstream III flies over Alaskan volcanoes


NASA completes imaging mission using Gulfstream

completed a 4 day mission in Alaska
using a Gulfstream-III research aircraft with an odd shaped pod fitted under
the fuselage.

During the four-day mission
from 1 to 4 August, the G-III flew several flights from Elmendorf Air Force
Base near Anchorage, Alaska. The UAVSAR synthetic aperture radar
installed in a pod slung under the belly of the G-III imaged volcanoes in the Aleutian Island chain to detect and measure small
changes in the Earth’s surface of geophysical interest. While the aircraft was
en route from its home base at NASA’s Dryden Aircraft Operations Facility in Palmdale, California, the
radar imaged volcanoes in the Cascade Range over California,
Oregon and Washington.

“All indications are that data were collected successfully,” said
scientist Paul Lundgren of NASA’s Jet Propulsion Laboratory in Pasadena, where the specialised radar was
developed. “However, to detect changes in activity requires computation of
differential interferograms from the new and previously collected data. This
processing….typically [takes] several months, so we will know months from now
whether there was any volcanic deformation over the past year.”

Differential Global Positioning System satellite information is being used in
conjunction with the aircraft’s precision autopilot to enable the aircraft to
repeat flight lines within 15 feet of the originals flown in August 2010. The
system depends on corrections received from Iridium and Inmarsat satellites.
The radar’s electronically steered antenna compensates for aircraft altitude
and heading changes as the radar makes repeat passes over areas of interest.

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