What is a digital orthophoto quadrangle (DOQ) or orthoimage?
A digital orthophoto quadrangle (DOQ)--or any orthoimage--is a computer-generated image of an aerial photograph in which displacements (distortions) caused by terrain relief and camera tilts have been removed. It combines the image characteristics of a photograph with the geometric qualities of a map.
Unlike an aerial photograph, an orthoimage has a uniform scale, so it can be used as a base map onto which other map information is overlaid. It is possible to measure directly on an orthoimage, just like other maps.
- Digital Orthophoto Quadrangle (DOQ)
- High Resolution Orthoimagery (HRO)
- National Agriculture Imagery Program (NAIP, NAIP Plus)