DOQ = USGS Digital Orthophoto Quadrangle: 1987 - 2006
'Orthophotos combine the image characteristics of a photograph with the geometric qualities of a map.  The primary digital orthophotoquadrangle (DOQ) is a 1-meter ground resolution, quarter-quadrangle (3.75 minutes of latitude by 3.75 minutes of longitude) image cast on the Universal Transverse Mercator projection …