Shrnutí

Popis

A Digital Orthophoto Quarter-Quadrangle (DOQQ) is a raster image in which displacement in the image caused by sensor orientation and terrain relief has been removed. An orthophoto combines the image characteristics of a photograph with the geometric qualities of a map. The geographic extent of the DOQQ is equivalent to a quarter of a 7.5-minute map (3.75 minutes of latitude and longitude) with overedge. The overedge ranges from a minimum of 300 meters to a maximum of 600 meters beyond the extremes of the NAD83 datum 3.75-minute latitude and longitude boundaries. DOQQs are produced with a 1-meter ground sample distance (GSD) and are cast on the Universal Transverse Mercator (UTM) projection on the North American Datum of 1983 (NAD83). Each DOQQ is produced to meet a National Map Accuracy Standard (NMAS) for 1:12000 scale maps (10.16 meters radial error at a 90% probability). The 2005 DOQQs were derived from the NM Statewide Orthophotography Project source imagery flown at 35,000 feet above average ground using multiple source images for each DOQQ. NM Statewide Orthophotography Project imagery was flown during the irrigation season, hence leaf-on for deciduous vegetation.