FORESTRY
REMOTE SENSING
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Super active
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Active
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Passive
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Nonpassive
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Detailed explanation-1: -Passive instruments detect natural energy that is reflected or emitted from the observed scene. Passive instruments sense only radiation emitted by the object being viewed or reflected by the object from a source other than the instrument.
Detailed explanation-2: -Remote sensing systems which measure energy that is naturally available are called passive sensors. Passive sensors can only be used to detect energy when the naturally occurring energy is available. For all reflected energy, this can only take place during the time when the sun is illuminating the Earth.
Detailed explanation-3: -Active sensors have their own source of light or illumination. In particular, it actively sends a pulse and measures the backscatter reflected to the sensor. But passive sensors measure reflected sunlight emitted from the sun. When the sun shines, passive sensors measure this energy.