Sonar stands for sound navigation ranging. It is defined as the technique used for determining the distance and direction of underwater objects with the help of sound waves. This technique is used by animals such as bats and whales.
Sonar systems are divided into three categories and they are:
- Active sonar: In this system, sound waves are generated such that they spread out and gets reflected by the target object. A receiver is used for analyzing these reflected signals.
- Passive sonar: Here, only receivers are used so as to analyze the characteristics of the reflected waves.
- The last category of the sonar system is used in the communication system which includes a projector as well as a receiver.