Australia observed by radar
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Weekly image: Week 47, 2006
Large image/
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Envisat, ESA’S environmental satellite, has taken these radar
images of Australia
In contrast to an image taken by an optical sensor this radar
image is in black and white and the brighter areas represent
rougher surfaces or high soil humidity. Google allows to dim the
radar image and to see the conventional satellite images below.
This reveals that mostly mountainous areas appear bright.
However also some salt lakes appear light, due to a dried out
and therefore cracked surface. Some highland in the north also
appear exceptionally bright because adjacent satellite tracks
from different seasonal (wet - dry) conditions have been used.
Technical information
Envisat, ESA’s environmental satellite, has acquired these
radar images of Australia during the period November 1 to
November 9, 2006. The images are acquired in the Global
Monitoring Mode (GMM) of the instrument that allows for the
first time global radar coverage of the Earth. The resolution is
approximately 1 km and the swath width of each satellite pass is
about 400 km. The radar signal from the ocean varies with
incidence angle, and therefore the images over the ocean are
much brighter on one side (closer to the satellite) than the
other (further away from the satellite).
More information about Radar imaging of the Earth can be
found
here.
The 1 kilometer resolution image for GoogleEarth can be
downloaded
here.
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