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Properties
of SAR.
Benefits
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A SAR is an active instrument - it transmits its own radiation. This
means it is not dependent on the sun and can operate continuously, day
and night.
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Microwave radiation is unaffected by cloud cover, fog, or
precipitation so it can image the Earth's surface in all weather
conditions.
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SAR observes structures at length scales other than those captured
by optical instruments. The two datasets are complementary and record
different properties.
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SAR is capable of continuous observation of dynamic phenomena such
as the monitoring of ocean currents and sea ice, and changes in water
and vegetation coverage.
Disadvantages
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At the resolutions typical of easily available SAR datasets, there
is little redundant information: objects like trees, vehicles and
buildings typically occupy only one or two pixels.
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SAR is highly dependent on maintaining precise time relationships
between the transmitted and received signals. All such coherent
imaging technologies suffer from the problem of speckle.
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