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The Ping, described as "hums and buzzes" whose "sound[s] scare sea animals." It was detected by shipboard sonars in the Fury and Hecla Strait of northern Canada during the summer of 2016. It was investigated by Canadian military authorities, who did not detect any anomalies on the seabed, where the sound originated.
Synthetic-aperture sonar (SAS) is a form of sonar in which sophisticated post-processing of sonar data is used in ways closely analogous to synthetic-aperture radar. Synthetic-aperture sonars combine a number of acoustic pings to form an image with much higher along-track resolution than conventional sonars.
Sonar also uses beamforming to compensate for the significant problem of the slower propagation speed of sound as compared to that of electromagnetic radiation. In side-look-sonars, the speed of the towing system or vehicle carrying the sonar is moving at sufficient speed to move the sonar out of the field of the returning sound "ping".
Sonar systems are generally used underwater for range finding and detection. Active sonar emits an acoustic signal, or pulse of sound, into the water. The sound bounces off the target object and returns an echo to the sonar transducer. Unlike active sonar, passive sonar does not emit its own signal, which is an advantage for military vessels.
Echo sounding or depth sounding is the use of sonar for ranging, normally to determine the depth of water . It involves transmitting acoustic waves into water and recording the time interval between emission and return of a pulse; the resulting time of flight , along with knowledge of the speed of sound in water, allows determining the distance ...
A 4-inch (100 mm) underwater locator beacon, with ballpoint pen for scale A ULB attached to a bracket on a cockpit voice recorder. An underwater locator beacon (ULB), underwater locating device (ULD), or underwater acoustic beacon is a device that emits an acoustic pulse intended to guide searchers equipped with a suitable receiver to the location of the beacon underwater.
Bistatic sonar is a sonar configuration in which transmitter and receiver are separated by a distance large enough to be comparable to the distance to the target. Most sonar systems are monostatic , in that the transmitter and receiver are located in the same place.
During sonar tests on submarines, it is said that the areas surrounding the sonar transducers had less fouling than the rest of the hull [citation needed]. Antifouling (the removal of biofouling ) has been attempted since ancient times, initially using wax, tar or asphalt.