passive sonar
Receives without transmitting
Passive sonar is a detection system that listens for sounds rather than emitting signals.
Unlike active sonar, which sends out pulses and measures their return, passive sonar simply receives acoustic energy—engine noise, propeller cavitation, whale calls.
Submarines use passive sonar to track vessels without revealing their own position: They switched to passive sonar to avoid detection.
- hydrophoneSubmersible sound sensor
- ambient noiseEver-present environmental audio
- pingBrief metallic tone
- echoReflected sound wave
- waterClear essential liquid
transducer · stealth · data recorder · sonobuoy · detection · Doppler effect · receiver · listen · silent running · time-domain analysis · acoustic shadow · underwater navigation · torpedo · click · hum · faint · submarine · whale song
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