Documents / FOIA release
This is a 1992 CIA History Staff monograph by Gregory W. Pedlow and Donald E. Welzenbach, originally classified Secret NOFORN and approved for release in 2013. It covers the CIA's manned overhead reconnaissance program from 1954 to 1974 and the two aircraft it developed, the U-2 and the A-12 OXCART. The history covers the U-2 overflights of the Soviet Union, the 1960 downing of Francis Gary Powers and later operations in Asia and Latin America. It also includes a section on U-2s, UFOs and Operation BLUE BOOK.
Read from the scan by GLM-OCR; expect the odd misread word.
Secret NOFORN
Chapter 2
52
U-2s equipped with the A-1 camera system also carried a Perkin-Elmer tracking camera using 2.75-inch film and a 3-inch lens. This device made continuous horizon-to-horizon photographs of the terrain passing beneath the aircraft. Because the A-1 system was new, it also included a backup camera system, a K-17 6-inch three-camera trimetrogon unit using 9-inch film.
While the A-1 system was still being developed, James Baker was already working on the next generation of lenses for high-altitude reconnaissance. Baker was a pioneer in using computers to synthesize optical systems. His software algorithms made it possible to model lens designs and determine in advance the effects that variations in lens curvatures, glass compounds, and lens spacings would have on rays of light passing through a lens. These "ray-tracing" programs required extensive computations, and, for this he turned to the most modern computer available, an IBM CPC (card-programmed calculator) installation at nearby Boston University. $ ^{17} $ Not linked to a story yet.
FOIA release, from the cia-readingroom collection. The PDF is mirrored here; the original link is above. The text was read from the page images by GLM-OCR; expect the odd misread word. 406 pages are in the text index: search them above, or from the library's search.