NHAP = National High-Altitude Aerial Photography: 1980 - 1989
'The National High Altitude Photography (NHAP) program, which was operated from 1980-1989, was coordinated by the U.S. Geological Survey as an interagency project to eliminate duplicate photography in various Government programs. The aim of the program was to cover the 48 conterminous states over a 5-year span. In the …