Excerpt

Satellite Earth Observation is a means of watching earth and indentifying objects and changes in it. Typical Earth Observations consist of Ground In-Situ monitoring by human observers and Overhead Observation by flying aircraft. Unlike these two methods, satellite Earth Observation has an advantage in the use of space with nearly a decade long in orbiting time and offers a wide scale of economy per unit of measured area. With innovation in the new improved sensor technology, in the very near future, the satellites would be able to identify objects as small as the size of a human head from the space, in which the current highest resolution 50 cm is very much closed but it is not clear enough to differentiate objects with this size

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