Aerial Imagery Source
NAIP Aerial Imagery of the continental U.S.
This digital ortho photography, predominantly 1 meter in resolution, covers the entire 48 states, and includes urban as well as agricultural and non-agricultural areas. In most cases this is the same imagery that is used in Google Maps and Google Earth, at the highest zoom levels, for all but large urban areas. This is the high resolution imagery where cars and houses can be seen.
The entire 48 states is flown over a multi-year cycle so the most current imagery, for a given state, may be from as early as 2006. 2009 imagery is available now and covers the majority but not all states. 2010 imagery will become available in the spring of 2011. We use the most current imagery available, unless requested otherwise.
The National Agriculture Imagery Program (NAIP) acquires this aerial imagery during the agricultural growing seasons in the continental U.S. The NAIP is administered by the USDA's Farm Service Agency (FSA) through its Aerial Photography Field Office. NAIP imagery is acquired at a one-meter ground sample distance (GSD) with a horizontal accuracy that matches within six meters of photo-identifiable ground control points, which are used during image inspection. The default spectral resolution is natural color (Red, Green and Blue, or RGB). Every attempt is made to achieve no more than 10% cloud cover, weather conditions permitting.