The National Map
Orthoimagery data typically are high resolution aerial images that combine the visual attributes of an aerial photograph with the spatial accuracy and reliability of a planimetric map. USGS digital orthoimage resolution may vary from 6 inches to 1 meter. The National Map offers free downloads of public domain, 1-meter orthoimagery for the conterminous United States with many urban areas and other locations at 2-foot or finer resolution. Further information and data download are available at: http://nationalmap.gov/viewer.html.