Photographic reconnaissance

Imagery intelligence (IMINT) is an intelligence gathering discipline which collects information via satellite and aerial photography. As a means of collecting intelligence, IMINT is a subset of intelligence collection management, which, in turn, is a subset of intelligence cycle management. IMINT is especially complemented by non-imaging MASINT electro-optical and radar sensors.

Although aerial photography was first used extensively in the First World War, it was only in the Second World War that specialized imagery intelligence operations were initiated. High quality images were made possible with a series of innovations in the decade leading up to the war. In 1928, the RAF developed an electric heating system for the aerial camera. This allowed reconnaissance aircraft to take pictures from very high altitudes without the camera parts freezing.

In 1939, Sidney Cotton and Flying Officer Maurice Longbottom of the RAF suggested that airborne reconnaissance may be a task better suited to fast, small aircraft which would use their speed and high service ceiling to avoid detection and interception. They proposed the use of Spitfires with their armament and radios removed and replaced with extra fuel and cameras. This led to the development of the Spitfire PR variants. These planes had a maximum speed of 396 mph at 30,000 feet with their armaments removed, and were used for photo-reconnaissance missions. The aircraft were fitted with five cameras which were heated to ensure good results.

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