orthophoto

thumb|right|Orthographic views project at a right angle to the datum plane. Perspective views project from the surface onto the datum plane from a fixed location. thumb|Aerophotogrammetry, orthophoto from unmanned aerial vehicle|drone, Città Alta, [[Bergamo, Italy.]] thumb|This photo is properly projected on elevation model, yet on a single building scale, a small tilt is noticeable. This is an orthophoto, but not a true orthophoto (not all vertical features are reprojected). thumb|This photo is assembled from several overlapping photos from UAV, completely removing any residual tilt of the buildings. This is a true orthophoto.

An 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. 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.