Cobra Mist

Cobra Mist was the codename for an Anglo-American experimental over-the-horizon radar station at Orford Ness, England.The site and buildings were then occupied by a radio transmitting station used mainly for the UK Foreign Office and the BBC World Service until 2011.In August 2015, the site and all the facilities previously held by the UK Foreign Office and the BBC (and prior to them the Ministry of Defence) were acquired by Cobra Mist Limited, a privately owned company.[4][b] With this successful demonstration, the US Air Force started plans to deploy a similar system in Turkey; providing coverage of much of the western part of the Soviet Union.Construction of the site started in mid-1967 with the buildings and support systems which had to be carefully shielded to avoid contamination from signals being reflected locally.[6] Through the early part of 1972 testing found a considerable amount of unexpected noise, which appeared as frequency shifting of the signal.A lengthy series of investigations into the source of the noise followed and, in desperation, the USAF eventually turned over the testing to a panel headed by SRI International.[7] The AN/FPS-95 antenna consisted of 18 individual strings radiating outward from a single point near the eastern shore of Orford Ness.[9] Key to the operation of any backscatter radar is the ability to filter out the huge return from the ground and sea, and capture only the objects of interest.
The former Cobra Mist building in October 2004
Radiating lines at the site
over-the-horizon radarOrford NessEnglandTurkeyradio transmitting stationForeign OfficeBBC World ServiceJoint Electronics Type Designation SystemNaval Research LaboratoryChesapeake BayCape CanaveralNevadaUS Air ForceSoviet UnionPlesetskSRI Internationalelectronic countermeasuresABM Treatyionospherepulse repetition frequencyDoppler effectgating outJindalee over-the-horizon radarDuga radarList of radarsList of military electronics of the United Statesgrid referencemushroom cloudpublic domainCobra BallCobra DaneCobra GeminiCobra JudyCobra KingAN/FPS-3AN/FPS-4AN/FPS-5AN/FPS-6AN/FPS-7AN/FPS-8AN/FPS-10AN/FPS-12AN/FPS-14AN/FPS-16AN/FPS-17AN/FPS-18AN/FPS-19AN/FPS-20AN/FPS-23AN/FPS-24AN/FPS-26AN/FPS-27AN/FPS-30AN/FPS-35AN/FPS-41AN/FPS-49AN/FPS-50AN/FPS-64AN/FPS-65AN/FPS-66AN/FPS-67AN/FPS-82AN/FPS-85AN/FPS-87AN/FPS-90AN/FPS-91AN/FPS-92AN/FPS-93AN/FPS-95AN/FPS-100AN/FPS-107AN/FPS-108AN/FPS-113AN/FPS-115AN/FPS-116AN/FPS-117AN/FPS-120AN/FPS-123AN/FPS-124AN/FPS-126AN/FPS-129AN/FPS-132United States Air ForceA/B/E/F/NL (II)A/B (I)S (II)