| description:
|
Orthophotos combine the image characteristics of a photograph with the geometric qualities of a map. The primary digital orthophotoquad (DOQ) is a 1-meter ground resolution, quarter-quadrangle (3.75-minute of latitude and 3.75-minute of longitude) image cast on the Universal Transverse Mercator Projection (UTM) on the North American Datum of 1983 (NAD83). The normal orientation data is by lines (rows) and samples (columns). Each contains a series of pixels ordered from west to with the order of the lines from north to south. The radiometric image values are stored as 256 gray levels ranging 0 to 255. |