Underwater Acoustics

 

Underwater Acoustics 

 
Submarines and other ships can be tracked either by passively listening to the underwater sound that a ship produces underwater or by listening to echoes of transmitted sound waves that reflect against a submarine (active). The ‘Measurement Building’ started researching underwater acoustics in 1938.

During WWII underwater acoustics was used to detect submarines and surface vessels. Initially, the technique was called ASDIC (Anti-Submarine Detection Investigation Committee); later the term sonar for “SOUND Navigation And Ranging” took off in analogy with “Radar” for Radio Detection And Ranging. Sonar only works much slower than radar because the speed of sound in water is only 1,500 m/s. By comparison, the speed of radio waves is 300,000 km/s. The underwater loudspeaker, also a microphone, which transmits sounds (active sonar) and which captures sounds (passive) and or the echoes (active) is called a transducer.

In  1946, the laboratory reluctantly restarted its underwater acoustics research. Since that time there have been many achievements:

Research facilities:

 

 

Research group Underwater Acoustics
Research group Underwater Acoustics