Robinson, A.H., Morrison, J.L., Muehrcke, P.C., Kimerling, A.J., Stephen Guptill, (1995) Elements of Cartography: John Wiley & Sons Inc., Canada, 6th ed.After a week+ of trial and error I wonder.Petrie, G., (1977), Transactions of the Institute of British Geographers: Orthophotomaps New Series, vol."Mosaicking of Aerial Photographic Maps Via Seams Defined by Bottleneck Shortest Paths". Fundamentals of Geographic Information Systems, John Wiley & Sons. Bolstad, P., (2005), GIS Fundamentals: A First Text on Geographic Information Systems, Eider Press, White Bear Lake, MN, 2nd ed.^ American Congress on Surveying and Mapping, American Society for Photogrammetry and Remote Sensing (1994), Glossary of the Mapping Sciences, American Society of Civil Engineers, p. 370, ISBN 9780784475706.^ BBC Tomorrow's World: How maps are corrected and updated using aerial photography and optical machinery."Digital orthophotography and GIS." ESRI Conference. Leica Photogrammetry Suite Orthorectification Software.Digital Orthophoto Quadrangle (DOQ) and Digital Orthophoto Quarter Quadrangle (DOQQ).A similar document, mostly used for disaster relief, is called a spatiomap.Īerial orthorectified image of a mine for volumetric measurements in stock pile reporting. Often these maps show additional point, line or polygon layers (like a traditional map) on top of the orthophotomosaic. The document (digital or paper) representing an orthophotomosaic with additional marginal information like a title, north arrow, scale bar and cartographical information is called an orthophotomap or image map. Orthophotomap of Oviedo city center, Spain.Īn orthophotomosaic is a raster image made by merging orthophotos - aerial or satellite photographs which have been transformed to correct for perspective so that they appear to have been taken from vertically above at an infinite distance. The orthophotomap contains additional roads, terrain elevation and bathymetry layers. Orthophotomap Orthophotomap of Rockport, Texas. The orthorectification is not always perfect and has side effect especially for the geometry of high-rise constructions. Production of orthophotos was historically achieved using mechanical devices. Some software can process the orthophoto and produce the linework automatically. 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). An orthoimage and a "rubber sheeted" image can both be said to have been "georeferenced" however, the overall accuracy of the rectification varies. A digital elevation model (DEM) is required to create an accurate orthophoto as distortions in the image due to the varying distance between the camera/sensor and different points on the ground need to be corrected. An orthorectified image differs from "rubber sheeted" rectifications as the latter may accurately locate a number of points on each image but "stretch" the area between so scale may not be uniform across the image. Orthophotographs are commonly used in geographic information systems ( GIS) as a "map accurate" background image. Unlike an uncorrected aerial photograph, an orthophoto can be used to measure true distances, because it is an accurate representation of the Earth's surface, having been adjusted for topographic relief, lens distortion, and camera tilt. This is a true orthophoto.Īn orthophoto, orthophotograph, orthoimage or orthoimagery is an aerial photograph or satellite imagery geometrically corrected ("orthorectified") such that the scale is uniform: the photo or image follows a given map projection. This photo is assembled from several overlapping photos from UAV, completely removing any residual tilt of the buildings. This is an orthophoto, but not a true orthophoto (not all vertical features are reprojected). This photo is properly projected on elevation model, yet on a single building scale, a small tilt is noticeable. Aerophotogrammetry, orthophoto from drone, Città Alta, Bergamo, Italy. Perspective views project from the surface onto the datum plane from a fixed location. Orthographic views project at a right angle to the datum plane. ( February 2009) ( Learn how and when to remove this template message) Please help to improve this article by introducing more precise citations. This article includes a list of general references, but it lacks sufficient corresponding inline citations.
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