Editing Imagery intelligence (section)

===Origins===
{{main|Aerial reconnaissance#History}}
{{see also|Aerial photography#History}}

[[File:Lockheed 12A G-AGTL Ringway 14.04.58 edited-2.jpg|thumb|[[Sidney Cotton]]'s [[Lockheed 12]]A, in which he made a high-speed reconnaissance flight in 1940.]]
Although [[aerial photography]] was first used extensively in the [[Aerial reconnaissance in World War I|First World War]], it was only in the [[Aerial reconnaissance in World War II|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.<ref>{{cite web|url=http://web.mit.edu/6.933/www/Fall2000/edgerton/www/pre-hee.html#aerial|title=Photography Before Edgerton}}</ref>

In 1939, [[Sidney Cotton]] and [[Flying Officer]] [[Maurice Longbottom (RAF officer)|Maurice Longbottom]] of the [[Royal Air Force|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 [[Supermarine Spitfire|Spitfires]] with their armament and [[radio]]s removed and replaced with extra fuel and cameras. This led to the development of the [[Supermarine Spitfire (early Merlin powered variants)#PR Mk I - Early Reconnaissance Versions|Spitfire PR]] variants. These planes had a maximum speed of 396&nbsp;mph<ref>{{cite book|title=Spies in the Sky |first=Taylor |last=Downing |isbn=9781408702802 |year=2011 |publisher=Little Brown Hardbacks (A & C) |pages=42}}</ref> 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.<ref>{{cite book|author=Cotton, Sidney|title=Aviator Extraordinary: The Sidney Cotton Story|publisher=Chatto & Windus|year=1969|page=169|isbn=0-7011-1334-0|url=https://books.google.com/books?id=TUHbAAAAMAAJ}}</ref>

The systematic collection and interpretation of the huge amounts of aerial reconnaissance intelligence data soon became imperative. Beginning in 1941, [[RAF Medmenham]] was the main interpretation centre for photographic reconnaissance operations in the [[European theatre of World War II|European]] and [[Mediterranean and Middle East theatre of World War II|Mediterranean]] theatres.<ref>{{cite book|title=Spies in the Sky |first=Taylor |last=Downing |isbn=9781408702802 |year=2011 |publisher=Little Brown Hardbacks (A & C) |pages=80–81}}</ref><ref name="buckscc">{{Cite web |url=https://ubp.buckscc.gov.uk/SingleResult.aspx?uid=%27TBC563%27 |title=Unlocking Buckinghamshire's Past |access-date=2014-01-11 |archive-date=2012-08-16 |archive-url=https://web.archive.org/web/20120816022825/https://ubp.buckscc.gov.uk/SingleResult.aspx?uid=%27TBC563%27 |url-status=dead }}</ref> The ''[[Central Interpretation Unit]]'' (CIU) was later amalgamated with the Bomber Command Damage Assessment Section and the Night Photographic Interpretation Section of No 3 Photographic Reconnaissance Unit, [[RAF Oakington]], in 1942.<ref name="rcahms">[http://aerial.rcahms.gov.uk/isadg/isadg.php?refNo=GB_551_NCAP/17 Allied Central Interpretation Unit (ACIU)]  {{webarchive|url=https://web.archive.org/web/20130312151307/http://aerial.rcahms.gov.uk/isadg/isadg.php?refNo=GB_551_NCAP%2F17 |date=March 12, 2013 }}</ref><ref>{{YouTube|NV5EbV43dZg|"Photographic Intelligence for Bombardment Aviation"}}</ref>

During 1942 and 1943, the CIU gradually expanded and was involved in the planning stages of practically every operation of the war, and in every aspect of intelligence. In 1945, daily intake of material averaged 25,000 negatives and 60,000 prints. Thirty-six million prints were made during the war. By [[VE-day]], the print library, which documented and stored worldwide cover, held 5,000,000 prints from which 40,000 reports had been produced.<ref name=rcahms/>

American personnel had for some time formed an increasing part of the CIU and on 1 May 1944 this was finally recognized by changing the title of the unit to the ''Allied Central Interpretation Unit'' (ACIU).<ref name=rcahms/> There were then over 1,700 personnel on the unit's strength. A large number of photographic interpreters were recruited from the [[Cinema of the United States|Hollywood Film Studios]] including [[Xavier Atencio]]. Two renowned archaeologists also worked there as interpreters: [[Dorothy Garrod]], the first woman to hold an Oxbridge Chair, and [[Glyn Daniel]], who went on to gain popular acclaim as the host of the television game show ''[[Animal, Vegetable or Mineral?]]''.<ref name=Crossbow/>

[[File:Peenemunde test stand VII.jpg|right|thumb|Aerial photograph of the missile [[Test Stand VII]] at [[Peenemünde Army Research Center|Peenemünde]].]]
[[Sidney Cotton]]'s aerial photographs were far ahead of their time. Together with other members of his reconnaissance squadron, he pioneered the technique of high-altitude, high-speed photography that was instrumental in revealing the locations of many crucial military and intelligence targets. Cotton also worked on ideas such as a prototype specialist reconnaissance aircraft and further refinements of photographic equipment. At its peak, British reconnaissance flights yielded 50,000 images per day to interpret.

Of particular significance in the success of the work of Medmenham was the use of [[stereoscopic]] images, using a between plate overlap of exactly 60%. Despite initial scepticism about the possibility of the German rocket technology, major operations, including the 1943 offensives against the [[V-2]] rocket development plant at [[Peenemünde Army Research Center|Peenemünde]], were made possible by painstaking work carried out at Medmenham. Later offensives were also made against potential launch sites at [[Wizernes]] and 96 other launch sites in northern France.

It is claimed that Medmanham's greatest operational success was "[[Operation Crossbow]]" which, from 23 December 1943, destroyed the [[V-1 (flying bomb)|V-1]] infrastructure in northern France.<ref name="Crossbow">[http://www.bbc.co.uk/programmes/b011cr8f "Operation Crossbow", BBC2, broadcast 15 May 2011]</ref> According to [[Reginald Victor Jones|R.V. Jones]], photographs were used to establish the size and the characteristic launching mechanisms for both the [[V-1 flying bomb]] and the [[V-2 rocket]].