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PROPULSION LABORATORYCALIFORNIA INSTITUTE OF TECHNOLOGYNATIONAL AERONAUTICS AND
SPACE ADMINISTRATIONPASADENA, CALIF. 91109. TELEPHONE (818) 354-5011PHOTO
CAPTION P-44703
October 3, 1994 Mount
Rainier, Washington L, C
bands This is a radar image of Mount Rainier in
Washington state. The volcano last erupted about 150 years ago and numerous
large floods and debris flows have originated on its slopes during the last
century. Today the volcano is heavily mantled with glaciers and snowfields.
More than 100,000 people live on young volcanic mudflows less than 10,000 years
old and, consequently, are within the range of future, devastating mudslides.
This image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic
Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on its 20th
orbit on October 1, 1994. The area shown in the image is approximately 59
kilometers by 60 kilometers (36.5 miles by 37 miles). North is toward the top
left of the image, which was composed by assigning red and green colors to the
L-band, horizontally transmitted and vertically, and the L-band, horizontally
transmitted and vertically received. Blue indicates the C-band, horizontally
transmitted and vertically received. In addition to highlighting topographic
slopes facing the space shuttle, SIR-C records rugged areas as brighter and
smooth areas as darker. The scene was illuminated by the shuttle's radar from
the northwest so that northwest-facing slopes are brighter and southeast-facing
slopes are dark. Forested regions are pale green in color; clear cuts and bare
ground are bluish or purple; ice is dark green and white. The round cone at the
center of the image is the 14,435-foot (4,399-meter) active volcano, Mount
Rainier. On the lower slopes is a zone of rock ridges and rubble (purple to
reddish) above coniferous forests (in yellow/green). The western boundary of
Mount Rainier National Park is seen as a transition from protected, old-growth
forest to heavily logged private land, a mosaic of recent clear cuts (bright
purple/blue) and partially regrown timber plantations (pale blue). The
prominent river seen curving away from the mountain at the top of the image (to
the northwest) is the White River, and the river leaving the mountain at the
bottom right of the image (south) is the Nisqually River, which flows out of
the Nisqually glacier on the mountain. The river leaving to the left of the
mountain is the Carbon River, leading west and north toward heavily populated
regions near Tacoma. The dark patch at the top right of the image is Bumping
Lake. Other dark areas seen to the right of ridges throughout the image are
radar shadow zones. Radar images can be used to study the volcanic structure
and the surrounding regions with linear rock boundaries and faults. In
addition, the recovery of forested lands from natural disasters and the success
of reforestation programs can also be monitored. Ultimately this data may be
used to study the advance and retreat of glaciers and other forces of global
change. -----Spaceborne Imaging Radar-C and
X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to
Planet Earth. The radars illuminate Earth with microwaves, allowing detailed
observations at any time, regardless of weather or sunlight conditions.
SIR-C/X-SAR uses three microwave wavelengths: the L-band (24 cm), the C-band (6
cm) and the X-band (3 cm). The multi-frequency data will be used by the
international scientific community to better understand the global environment
and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and
ground studies, will give scientists clearer insights into those environmental
changes which are caused by nature and those changes which are induced by human
activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was
developed by the Dornier and Alenia Spazio companies for the German space
agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian
space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche
Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in
science, operations and data processing of X-SAR.
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