Answer: The National High Altitude Photography (NHAP) program was initiated in
1980 and coordinated by the U.S. Geological Survey (USGS)
to acquire aerial photography of the 48 conterminous United States every
5 years. This interagency program was designed to eliminate duplicate
efforts in various Government programs and to maximize the use of
Government funds to build a uniform archive for multiple purposes. In
1987, the program name was changed to the National Aerial Photography
Program (NAPP) in recognition of modifications in the user requirements
and flight specifications.
The NAPP photography are acquired at 20,000 feet above mean terrain
with a 6 inch focal length lens. The flight lines are quarter quad-centered
on the 1:24,000-scale USGS maps. NAPP photographs have an approximate
scale of 1:40,000, and are acquired on black-and-white panchromatic (B/W) or color infrared (CIR)
film, depending on state or federal requirements.
The NHAP photography were acquired at 40,000 feet above mean terrain and
flight lines were centered on the 1:24,000-scale USGS map series. Two
different camera systems were used; a 6 inch focal length lens was used to
acquire B/W film at an approximate scale of 1:80,000 and an
8.25 inch lens was used to acquire CIR film at an approximate
scale of 1:58,000. |
