ERTH 20 Lecture Notes - Lecture 7: Aerial Photography, Orthophoto, Multispectral Image
13 Oct 2020
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Document Summary
Throughout most of history, maps were the only tools available to depict anything more than a tiny portion of earth"s surface with any degree of accuracy. Remote sensing: refers to any measurement or acquisition of information by a recording device that is not in physical contact with the object under study in this case, earth"s surface. the use of satellites revolutionized remote sensing. Aerial photography was almost the only form of remote sensing used for geographic purposes until the 1960s. Photogrammetry: the science of obtaining reliable measurements and mapping from aerial photographs had developed. Aerial photographs now available in digital form from agencies such as the usgs remain an important source of largescale geographic imagery. Orthophoto maps: are multicolored, distortion-free photographic maps prepared from aerial photographs or digital images. An orthophoto can show the landscape in much greater detail than a conventional map, but retains the map characteristic of a common scale that allows precise measurement of distances.
