A History of Military Mapping Camera Development – 1964

“For many years the Army’s Corps of Engineers has held the prime responsibility for the military development of map plotting equipment and for topographic mapping techniques in general. With the advent of the airplane, responsibility for the development of mapping cameras and other airborne mapping and surveying equipment was placed with the Army Air Corps. As a result, in 1920, the Army organized, at what is now Wright-Patterson Air Force Base, the Wright Field Military Detachment. This group was assigned as a branch of the Engineer Board at Fort Belvoir, Virginia, in the early part of World War II. The Engineer Board was reorganized several years later to form the U. S. Army Engineer Research and Development Laboratories. The present aerial mapping liaison group at Wright-Patterson Air Force Base is now a part of the U. S. Army Engineer Geodesy, Intelligence and Mapping Research and Development Agency, Fort Belvoir, Virginia, which operates directly under the Chief of Engineers.

The past forty years has seen the development in the Air Force of two lines of aerial cameras: the reconnaissance series and the mapping series. This division in development was influenced by the differing needs of the Army and the Air Force. In its prime responsibility for targeting, charting and reconnaissance interpretation, the Air Force has insisted that the major consideration in the development of reconnaissance cameras be the enhancement of photographic resolution. Hence, work in this area has included the development of lenses with high resolving power, films capable of producing high resolution, film magazines with image-motion compensation capabilities, and gyroscopically stabilized aerial camera mounts which reduce vehicle vibrations and acceleration effects.

The prime requisite of the Corps of Engineers for a mapping camera is a high degree of dimensional stability in the camera-lens-film
combination to produce photography capable of direct application to map compilation. Therefore, mapping camera development has been characterized by the production of frame-type cameras having low-distortion lenses, lens cones fabricated from alloys providing high structural stability and with fiducial markers placed on the lens cone
rather than on the magazine, also between-the-lens shutters, and appropriate data recordings which appear on the film negative
between frames. The cameras are stocked with low differential distortion, topographic base films, and are installed in stabilized aerial camera mounts. Development of mapping cameras is accomplished by the Air Force upon imposition of Corps of Engineers requirements. This work has been supported actively through the years by the previously mentioned Corps of Engineers personnel who have been assigned to duty at Wright-Patterson Air Force Base.

As early as 1955, Dr. James Baker was commissioned by the Air Force to design a low distortion mapping lens which would have a higher amount of photo resolution than the current Metrogon and Planigon lenses; these average about 22 and 24 lines/mm, respectively, in AWAR. The resulting Type T-ll lens, later called the Geocon I, proved to have lens distortions of less than 10 microns; its resolution measured 52 lines/mm on-axis and 35 lines/mm AWAR. The lens was mounted in a T-ll camera body for flight testing. The full F/5.6 speed of the lens, however, could not be realized in the prototype camera, which produced a maximum aperture of only F/8. This camera subsequently was used in high-speed, high-altitude flight tests.”

Reference: ROBERT G. LIVINGSTON, “A History of Military Mapping Camera Development,” Photogrammetric Engineering, p. 97-110, January 1964.