Aerial Imagery

Historically, aerial photos were captured by either large organization or small companies with access to an airplane.  The US government made many of its aerials freely available, both georeference (DOQ) and not georeferenced (NAPP).  There were large companies like AirPhotoUSA that gathered and licensed aerials.  Since around 2005, most aerial companies have been merged into global providers like DigitalGlobe which handle both aerial and space imagery.

Georectification

USGS DOQ

USGS NAPP (National Aerial Photography Program) and NAHP

Recent USGS