Sonar is an equipment that works from the emission of sound waves and is used for the detection and location of objects at the bottom of the oceans.
Sonars are instruments commonly used by ships to detect and locate objects on the seafloor . This equipment is indispensable for war purposes, given that it locates enemy submarines, and is widely used by fishing vessels to find shoals.
Sonars work from the emission of sound pulses , which collide with obstacles and return to the source. Knowing the value of the propagation speed of sound pulses in the water and the time between their emission and reception, it is possible to determine the distance of an obstacle or submarine.
Sonar working principle
The speed and direction of propagation of sound waves in water vary according to the temperature, salinity and depth of the water. The speed of sound , for example, increases with increasing temperature .
Difference between sonar and radar
Radars are equipment that have the same function as sonars: locate different objects. The big difference is that radars use radio waves ( electromagnetic waves ) to detect objects. The advantage is that these waves do not need a propagation medium and can be transmitted in a vacuum.
The sound waves emitted by sonars are mechanical and depend on a propagation medium that favors their transmission for a better operation of the sonar .
Damage caused by sonar
Autopsies performed on dolphins and whales killed in the Mediterranean Sea in 2002 indicated that the animals died as a result of disorientation and excessive pain generated by the sonar sounds of military and commercial vessels. The high frequency of the sonars causes pain in the animals, which are stressed, and can die due to hemorrhages generated after the rupture of their eardrums or by colliding with ships and other obstacles.