Category talk:01 Introduction to remote sensing
The term "remote sensing" was first used in the 60s when space technology, computer processing, storage and photosensitve sensor elements were in progress. The beginning of the early history of remote sensing can be dated much earlier to the invention of photography by Niepce, Daguerre and Talbot in the 19th century.
In many textbooks, remote sensing is defined as "measuring without being in direct contact with the object of interest". More preciseley, the term "sensing" is directly related to the human sensory system of vision. We may understand the natural principle of human vision and recognition as a protoype for designing a technology for information retrieval by measuring variations of electromagnetic radiation. The function of human eyes consisting of lenses and photosensitive rods and cones of the retina are applied in photography as cameras composed of objective lenses, analogue film emulsions or CCD sensor elements. The term "remote" is related to applications of distant vision from an elevated point similar to a bird's view to fly and observe the landscape from above. Thus, close-range photogrammetry and terrestrial laser scanning are not in focus but can be seen as early stages of remote sensor development before mounting on manned (e.g. aircraft) or unmanned (e.g. satellite) platforms. A general definiton:
remote sensing is the science and technology of information retrieval on objects by measuring electromagnetic radiation from elevated platforms.