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An orthophoto, orthophotograph or orthoimage is an aerial photograph geometrically corrected ("orthorectified") such that the scale is uniform: the photo has the same lack of distortion as a map. Unlike an uncorrected aerial photograph, an orthophotograph can be used to measure true distances, because it is an accurate representation of the Earth's surface, having been adjusted for topographic relief,〔Smith, Gary S. "DIGITAL ORTHOPHOTOGRAPHY AND GIS." ESRI Conference. http://proceedings.esri.com/library/userconf/proc95/to150/p124.html〕 lens distortion, and camera tilt. Orthophotographs are commonly used in the creation of a Geographic Information System (GIS). Software can display the orthophoto and allow an operator to digitize or place linework, text annotations or geographic symbols (such as hospitals, schools, and fire stations). Some software can process the orthophoto and produce the linework automatically. Production of orthophotos was historically achieved using mechanical devices. 〔(BBC Tomorrow's World: How maps are corrected and updated using aerial photography and optical machinery. 18 December 1970. )〕 == See also == * ImageStation Suite * Aerial Photography * Digital Orthophoto Quadrangle (DOQ) and Digital Orthophoto Quarter Quadrangle (DOQQ) * Leica Photogrammetry Suite Orthorectification Software * GRASS GIS (i.ortho.photo module) * Photogrammetry * Photomapping * TopoFlight * Socet set Orthophoto Software * U.S. Geological Survey * Rational Polynomial Coefficient 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「orthophoto」の詳細全文を読む スポンサード リンク
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