Search results
Results From The WOW.Com Content Network
Output of a computer model of underwater acoustic propagation in a simplified ocean environment. A seafloor map produced by multibeam sonar. 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.
Due to the absorption characteristics of seawater, ultrasound (sound at frequencies greater than human hearing, or approximately greater than 20,000 hertz) is not used for long-range underwater communications. The higher the frequency, the faster the sound is absorbed by the seawater, and the more quickly the signal fades.
A common use of ultrasound is in underwater range finding; this use is also called sonar. An ultrasonic pulse is generated in a particular direction. If there is an object in the path of this pulse, part or all of the pulse will be reflected back to the transmitter as an echo and can be detected through the receiver path. By measuring the ...
Sonar (sound navigation and ranging or sonic navigation and ranging) [2] is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances , communicate with or detect objects on or under the surface of the water, such as other vessels. [3]
The ultrasonic range refers to the very high frequencies: 20,000 Hz and higher. ... Underwater acoustics is the scientific study of natural and man-made sounds ...
USBL (ultra-short baseline, also known as SSBL for super short base line) is a method of underwater acoustic positioning. A USBL system consists of a transceiver, which is mounted on a pole under a ship, and a transponder or responder on the seafloor, on a towfish, or on an ROV. A computer, or "topside unit", is used to calculate a position ...
Underwater acoustic communication is a technique of sending and receiving messages in water. [1] There are several ways of employing such communication but the most common is by using hydrophones . Underwater communication is difficult due to factors such as multi-path propagation , time variations of the channel, small available bandwidth and ...
A depiction of the ultrasound signals emitted by a bat, and the echo from a nearby object. Echolocation, also called bio sonar, is a biological active sonar used by several animal groups, both in the air and underwater.