"Underwater acoustics (also known as hydroacoustics) is the study of the propagation of sound in water and the interaction of the mechanical waves that constitute sound with the water, its contents and its boundaries."
Studies how sound behaves in water and how it can be used to detect and communicate underwater.
"Typical frequencies associated with underwater acoustics are between 10 Hz and 1 MHz."
"The propagation of sound in the ocean at frequencies lower than 10 Hz is usually not possible without penetrating deep into the seabed, whereas frequencies above 1 MHz are rarely used because they are absorbed very quickly."
"Hydroacoustics, using sonar technology, is most commonly used for monitoring of underwater physical and biological characteristics."
"Hydroacoustic sensing involves 'passive acoustics' (listening for sounds) or active acoustics making a sound and listening for the echo, hence the common name for the device, echo sounder or echosounder."
"There are a number of different causes of noise from shipping. These can be subdivided into those caused by the propeller, those caused by machinery, and those caused by the movement of the hull through the water."
"One of the main causes of hydroacoustic noise from fully submerged lifting surfaces is the unsteady separated turbulent flow near the surface's trailing edge that produces pressure fluctuations on the surface and unsteady oscillatory flow in the near wake."
"The relative motion between the surface and the ocean creates a turbulent boundary layer (TBL) that surrounds the surface. The noise is generated by the fluctuating velocity and pressure fields within this TBL."
"The field of underwater acoustics is closely related to a number of other fields of acoustic study, including sonar..."
"Hydroacoustics can be used to detect the depth of a water body (bathymetry), as well as the presence or absence, abundance, distribution, size, and behavior of underwater plants and animals."
"Hydroacoustic sensing involves 'passive acoustics' (listening for sounds) or active acoustics making a sound and listening for the echo..."
"These can be subdivided into those caused by the propeller, those caused by machinery, and those caused by the movement of the hull through the water."
"Hence the common name for the device, echo sounder or echosounder."
"The unsteady separated turbulent flow near the surface's trailing edge that produces pressure fluctuations on the surface and unsteady oscillatory flow in the near wake."
"The field of underwater acoustics is closely related to a number of other fields of acoustic study, including... acoustical oceanography..."
"Frequencies above 1 MHz are rarely used because they are absorbed very quickly."
"Hydroacoustics is most commonly used for monitoring of underwater physical and biological characteristics."
"The interaction of the mechanical waves that constitute sound with the water, its contents and its boundaries."
"The relative motion between the surface and the ocean creates a turbulent boundary layer (TBL) that surrounds the surface."
"The field of underwater acoustics is closely related to a number of other fields of acoustic study, including... bioacoustics..."