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Imagery analysis is the extraction of useful information from bi-dimensional graphic formats, including screen shots. This includes color and black-and-white photographs, infra-red photographs and video, radar screens and synthetic aperture radar formats, ultrasound, EKG, EEG, MRI, echo cardiograms, seismographs and others. In short, any type of sensor-related data projected in 2- and 3-D formats qualifies as imagery. ==Origins== Prior to the invention of early photography, military commanders depended on scouts that would survey or recon enemy activity, depending on simple eyesight and human memory. Once photography became available, tactical information became frozen in time, details could be preserved, enhancing the quality of available information. World War I saw the start of ground-based and aerial photographic collection. For the first time commanders were able to access timely and accurate intelligence. Such was the value of this type of information that observers in tethered balloons and scout planes were attacked, first with crude weapons and later escalating to machine guns and the development of the fighter aircraft. Frank Luke, an American pilot procured incendiary ammunition and used it to destroy numerous enemy observation balloons, gaining the title of ''Balloon Buster''. The end of the war resulted in the scaling down of tactical and strategic capabilities, resulting in an almost dormant state in the development of photographic analysis. The perceived threat from Germany and Japan revived the collection and analytical capabilities of the major powers and helped military planners including U.S. General Dwight D. Eisenhower prepare for the next war. In the 1930s experiments with film media and its processing resulted in the introduction of film that could now detect non-visible wavelengths in the infra-red spectrum. One of the first applications was the use by those associated with rare art collections. Previously invisible details made it possible to detect and deter forgeries. Radar made its appearance during World War II, primarily in its early warning capability. In the early days of the Cold War, Soviet troops would use a directional radar beacon to lure surveillance aircraft toward their airspace in order to shoot them down. By this time radar scopes became available in larger aircraft monitoring Soviet-controlled border areas. Having these scopes made early radar navigation possible, indeed, in photos released by the Soviet air force, pictures were taken of the screens, documenting this use. The importance of tactical information is shown in the case of Operation Market-Garden, the aerial invasion of the Netherlands on Sep 17, 1944. Photo missions revealed the presence of two Panzer Divisions in the city of Arnhem, a bridgehead at the farthest reach of those airborne troops assigned. British intelligence Major Brian Urquhart warned his commander of the threat, but an overpowering optimism cause by the recent collapse of the Western front overruled any possibility of an objective threat assessment, resulting in a night-time river crossing in which out of 10,000 members of the British 1st Airborne Division that jumped into Arnhem, only 2,600 survivors would reach the southern shore 9 days later. In spite of the introduction of color film, photo interpreters to this day continue to use black and white because of the greater detail available. The early Cold War era also saw the introduction of strategic collection. In tactical collection, analysts count guns; strategic collection includes butter. The categories of collection is, of course, classified. The post-Vietnam era saw the introduction of airborne infra-red sensors. Differences in temperatures between objects and their surroundings made it possible to detect targets on the ground. These early systems would record data which would be accessed once the aerial platform would land. Later developments in transmission technology would provide periodic data dumps and would further evolve into real-time collection. Synthetic aperture radar would soon be developed in the later part of the Cold War. The concept of an optical camera aperture affecting the image acquisition process would be emulated with radar waves, providing an undisclosed amount of detail. One clue would be the NASA photo released in the late 1980s showing a previously hidden African dry riverbed. This is also about the time when ultrasound would make its appearance. For the first time it was possible to view variations in tissue density which made it possible to detect possible tissue and organ anomalies. Another application was that of detecting material flaws in manufacturing. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Imagery analysis」の詳細全文を読む スポンサード リンク
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