What is sonar and how does it work?

Sonar stands for Sound Navigation And Ranging. It is a device that is used to find the distance, direction, and speed of underwater objects like, water hills, valleys, icebergs, submarines, sunken ships, etc. SONAR works on the principle of reflection (echo) of sound waves from the object.

A sonar device sends pulses of sound waves down through the water. When these pulses hit objects like fish, vegetation, or the bottom, they are reflected back to the surface. The sonar device measures how long it takes for the sound wave to travel down, hit an object, and then bounce back up.

Sonar systems are of two basic types – active and passive. In active sonar, the system emits a pulse of sound and then the operator listens for echoes. In passive sonar, the operator listens to sounds emitted by the object one is trying to locate.