The system was developed in the UK at the Telecommunications Research Establishment by Robert Hanbury Brown and John William Sutton Pringle. Rebecca was essentially an ASV radar fit to a new broadcaster unit, while the Eureka system was all-new. Initial production began in 1943, and the system was used for dropping supplies to resistance fighters in occupied Europe, after delivery of the portable Eureka unit. The US Army Air Force started production in the US as well, and both examples could be used interchangeably. Over time, the Rebecca/Eureka found a number of other uses, including blind-bombing, airfield approach, and as a blind-landing aid in the BABS (Beam Approach Beacon Signal) form.