were switched together. These installations, called "Wassermann" (German: Aquarius), not only had greater range but were also more accurate. Countermeasures To counter Freya, the British used equipment called 'Moonshine'. Carried by Boulton Paul Defiant aircraft of the Special Duties Flight (later No. 515 Squadron RAF), a single set retransmitted a portion of the Freya signal amplifying the apparent return. Eight planes with 'Moonshine' could mimic a force of 100 bombers. A second countermeasures system, "Mandrel" was a noise jammer carried by aircraft of No. 100 Group RAF which overwhelmed the signals from Freya. Individual aircraft were sent to orbit fixed positions off the enemy coast. By using nine aeroplanes, a gap could be knocked into the German's radar coverage, while further jammers were carried in the bomber stream to counter the inland Freya network. Post-war use One FuMG 80 Freya radar, after modification, was installed in 1957/8 at the Ondřejov Observatory in Czechoslovakia and served as meteorite tracking radar until 2006. Before then it was used at the Pardubice Airport, under name RZ III. Notes Bibliography Brew, Alex. The Defiant File. Tunbridge Wells, Kent, UK: Air-Britain (Historians), 1996. . Price, Alfred. Instruments of Darkness: The History of Electronic Warfare. St Albans, UK: Granada, 1979. . Swords, Sean S. Technical History of the Beginnings of Radar, London: IEE/Peter Peregrinus, 1986. . Fritz Trenkle: Die deutschen Funkführungsverfahren bis 1945, Dr. Alfred Hüthig Verlag, Heidelberg 1987, Harry von Kroge: GEMA-Berlin – Geburtsstätte der deutschen aktiven Wasserschall- und Funkortungstechnik, 1998, Helmut Bukowski: Radarkrieg und Nachtluftverteidigung, VDM Verlag, Zweibrücken 2007, See also Würzburg radar List of World War II electronic warfare equipment Operation Taxable Operation Glimmer Battle of the Beams External links Deflating British Radar Myths of World War II A comparison of contemporary British and German radar technologies and their use Das Jahrhundert des Radars von Dr. Wolfgang Holpp, EADS (PDF-Datei; 3,6 MB) Ehemalige Standorte von Radaranlagen World War II German radars Radar networks Military equipment introduced in the 1930s