A secure location near the area under surveillance where the signal from a listening device is received.
Description based on Crypto Museum, according to which a bug is usually a small radio transmitter that picks up conversations in a room or on a telephone line; its signal is received at the listening post.1
An example: according to the CIA, the bug hidden in the carving of the Great Seal in the US ambassador's residence in Moscow (1945–1952) was activated by a high-frequency signal from a car parked outside, and sounds from the room were relayed to an external receiver (see passive bug).2
In communist Poland, receiving and transcribing intercepted conversations was the job of the SB's “T” division; reports (komunikaty) were drawn up from surveillance and eavesdropping, and surveillance was carried out from, among other places, covert observation posts.3,4,5
Sources
- Crypto Museum, Glossary of covert expressions
- CIA, Compromise of the Great Seal
- Institute of National Remembrance, IPN archival inventory – Glossary, letter T (in Polish)
- Institute of National Remembrance, IPN archival inventory – Glossary, letter K (in Polish)
- Institute of National Remembrance, IPN archival inventory – Glossary, letter Z (in Polish)
Checked: 4 November 2026