The Searchlight Experimental Establishment, or SLEE, was a Royal Engineers research group who studied the improvement of

searchlight A searchlight (or spotlight) is an apparatus that combines an extremely bright source (traditionally a carbon arc lamp) with a mirrored parabolic reflector to project a powerful beam of light of approximately parallel rays in a particular dir ...

s and other

anti-aircraft Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based, ...

systems like sound locators and predictors. The SLEE initially formed up at

Woolwich Common Woolwich Common is a common in Woolwich in southeast London, England. It is partly used as military land (less than 40%) and partly as an urban park. Woolwich Common is a conservation area. It is part of the South East London Green Chain. It is a ...

in 1917 during

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

as a small group within the

Corps of London Electrical Engineers Corps (; plural ''corps'' ; from French , from the Latin "body") is a term used for several different kinds of organization. A military innovation by Napoleon I, the formation was first named as such in 1805. The size of a corps varies great ...

to research

anti-aircraft artillery Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based, ...

and searchlights. In 1919, they took over sound locator development and began the acoustic mirror program that stretched into the 1930s before it was replaced by

radar Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...

. In 1924 the group moved to

RAF Biggin Hill London Biggin Hill Airport is an operational general aviation airport at Biggin Hill in the London Borough of Bromley, located south-southeast of Central London. The airport was formerly a Royal Air Force station RAF Biggin Hill, and a sma ...

and was renamed the Air Defence Experimental Establishment, or ADEE.

References

* Military research establishments of the United Kingdom 20th-century military history of the United Kingdom {{mil-stub