| Abstract: | Abstract An important landmark event in the history of aerial photography in the United States occurred in the 1980s. The entire conterminous 48 state area was photographed for the first time at two uniform scales and in two emulsions. A second cycle of coverage of the same area was begun in 1987 and will be completed in 1992. These photographs are a valuable resource in all fields of geography because they are linked to the U.S. Geological Survey 7.5-minute series of quadrangles. They also will display all parts of the conterminous U.S. at two recent periods of time, thereby facilitating change detection analysis studies. Color infrared and black-and-white prints on paper are available and will be useful for stereoscopic examination as well as standard measurements and interpretation. The use of diapositives and color transparencies in readily available projection devices is described and a classroom example of their use is portrayed. Sources for these photographs and ordering procedures are indicated. |
