Passive Acoustics

Passive acoustics is the action of listening for sounds, often at specific frequencies or for purposes of specific analyses.

As applied to underwater acoustics, also termed hydroacoustics or SONAR, passive acoustics can be used to listen for underwater explosions, earthquakes, volcanic eruptions, sounds produced by fish and other animals, vessel activity or aquatic detecting equipment (as in hydroacoustics to track fish).

Hydroacoustics

Sonar	Active acoustics Baffles (submarine) Bistatic sonar Echo sounding Fessenden oscillator GLORIA sidescan sonar Multibeam echosounder Passive acoustics Scientific echosounder Side-scan sonar Sonar beamforming Sonobuoy Surveillance Towed Array Sensor System Synthetic aperture sonar Towed array sonar Upward looking sonar

Ocean acoustics	Acoustic network Acoustic release Acoustic Doppler Current Profiler Acoustic Seabed Classification Acoustical oceanography Hydrophone Long baseline acoustic positioning system Ocean acoustic tomography Short baseline acoustic positioning system Sofar bomb SOFAR channel Sound speed gradient Sound velocity probe Ultra-short baseline Underwater acoustics Underwater acoustic communication Underwater acoustic positioning system

Acoustic ecology	Acoustic survey in fishing Acoustic tag Animal echolocation Beached whale Fishfinder Fisheries acoustics Hearing range of marine mammals Marine mammals and sonar Whale song

Related topics	Acoustic signature Bioacoustics Biophony Ecoacoustics Geophysical MASINT Hydrographic survey Noise map Soundscape

Famous quotes containing the word passive:

“...if you are to gain any great amount of good from the world, you must attain a passive condition of mind. ...it is never to be forgotten that it is the rest of the world and not you that holds the great share of the world’s wealth, and that you must allow yourself to be acted upon by the world, if you would become a sharer in the gain of all the ages to your own infinite advantage.”
—Anna C. Brackett (1836–1911)