A Digital Orthographic Quarter-Quad, DOQQ, is a digitized image of an aerial photograph, corrected for displacements caused by camera angle and relief. The result is a spatially accurate image with planimetric features appearing in their true geographic positions. Distortion corrections are made through georectification (features on the map are linked to their real world positons through a coordianate system, datum, and projection) and orthrectification (distortion is removed so that the photo can be used as a flat map; ground features are displayed in their true positions, allowing for more accurate measurement of distance, areas, angles, and positions). Orthophotos combine the image characteristics of a photograph with the geometric qualities of a map.
The above DOQQ is of Brandywine, British Columbia.
http://www.wr.udel.edu/cb/b17doqqqpuzzle.jpg
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