Orthophoto
Encyclopedia
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
, 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.
Aerial photography
Aerial photography is the taking of photographs of the ground from an elevated position. The term usually refers to images in which the camera is not supported by a ground-based structure. Cameras may be hand held or mounted, and photographs may be taken by a photographer, triggered remotely or...
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
Topography
Topography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...
, lens distortion
Barrel distortion
In geometric optics and cathode ray tube displays, distortion is a deviation from rectilinear projection, a projection in which straight lines in a scene remain straight in an image...
, and camera tilt.
Orthophotographs are commonly used in the creation of a Geographic Information System
Geographic Information System
A geographic information system, geographical information science, or geospatial information studies is a system designed to capture, store, manipulate, analyze, manage, and present all types of geographically referenced data...
(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.
See also
- Aerial PhotographyAerial photographyAerial photography is the taking of photographs of the ground from an elevated position. The term usually refers to images in which the camera is not supported by a ground-based structure. Cameras may be hand held or mounted, and photographs may be taken by a photographer, triggered remotely or...
- Leica Photogrammetry SuiteLeica Photogrammetry SuiteLeica Photogrammetry Suite is a software application for performing photogrammetric operations on imagery and extracting information from imagery...
Orthorectification Software - GRASS GISGRASS GISGRASS GIS is a free, open source geographical information system capable of handling raster, topological vector, image processing, and graphic data....
(i.ortho.photo module) - PhotogrammetryPhotogrammetryPhotogrammetry is the practice of determining the geometric properties of objects from photographic images. Photogrammetry is as old as modern photography and can be dated to the mid-nineteenth century....
- PhotomappingPhotomappingPhotomapping involves the process of drawing a map from a photographic base. “In all likelihood, computer map making, including analogue processing, will have replaced manual map making for well over 90 per cent of all maps".-Principles and Definitions:...
- TopoFlightTopoFlightTopoFlight is a three-dimensional flight planning software that was originally conceived by a team of experts in the mapping industry, in use since 2003...
- Socet set Orthophoto SoftwareSOCET SETSOCET SET is a software application that performs functions related to photogrammetry. It is developed and published by BAE Systems. SOCET SET was the first commercial digital photogrammetry software program...
- U.S. Geological Survey