Listening station
A listening station is a facility established to monitor radio and microwave signals and analyse their content to secure information and intelligence for use by the security and diplomatic community and others or to make local transmissions more widely available.
Y-stations were British Signals Intelligence collection sites initially established during World War I and later used during World War II.
Examples are BBC Monitoring at Caversham, RAF Menwith Hill, Harrogate and Government Communications Headquarters, Cheltenham; London Listening Station.
