# Ferret Aircraft **Entity class:** System **Research spine:** [[research/Chronology of Signals, Silos, and Sovereign Software - Research|Chronology of Signals, Silos, and Sovereign Software]] ## Definition Ferret aircraft were reconnaissance platforms that approached hostile territory to detect radar emissions, identify frequencies, and locate emitters without relying on active transmission. ## Chronological Proximity They operated during the 1942–1945 expansion of the [[wiki/Radio Research Laboratory|Radio Research Laboratory]] and the Allied jamming campaign. ## Relational Proximity Their search receivers supported [[wiki/Passive Electromagnetic Reconnaissance|passive electromagnetic reconnaissance]] and supplied the measurements needed for [[wiki/Radar Countermeasures|radar countermeasures]]. ## Collection Routes [[collections/The Civilian Intelligence Marketplace|The Civilian Intelligence Marketplace]] · [[collections/Terrorism, Counterterrorism, and the Intelligence Environment|Terrorism, Counterterrorism, and the Intelligence Environment]] · [[wiki/Signals, Silos, and Sovereign Software|Signals, Silos, and Sovereign Software]] ## Sources / Provenance - [[research/Chronology of Signals, Silos, and Sovereign Software - Research|Chronology of Signals, Silos, and Sovereign Software - Research]].