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Sonar Working

Last updated date: 05th Mar 2024
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What is a SONAR?

SONAR is an acronym that stands for Sound Navigation and Ranging, used in detecting, measuring distance and determining the direction of an object on or under the water. It is based on the principle of reflection (echo) of sound waves from an object.

SONAR works by calculating echo. Once you know the speed of sound in water and the time it takes for the signal to return, you can determine an object's distance. SONAR is also used for the device to transmit and detect sound.

Types of SONAR

There are two types of SONAR: Active and Passive.

  • Passive SONAR simply listens to the sounds of water. It listens for marine life and other ships that may be nearby or using active SONAR.

  • Active SONAR, on the other hand, actively sends pulses of sound and listens for how long they take to return when they 'bounce' off an object.

How Does a SONAR Device Work?

SONAR works using ultrasonic waves or ultrasound. The entire device is installed on the ship. It has a transmitter and detector.

SONAR Device

SONAR Device

  • The transmitter generates powerful ultrasonic waves or ultrasounds.

  • These waves travel through water and hit objects submerged or on the seabed.

  • After striking the object or seabed, the detector reflects and receives the wave.

  • The ultrasonic waves are then converted into electrical signals by the detector.

  • These signals are studied to determine the underwater condition and obstacles.

Uses of SONAR

  • SONAR is used for underwater communication between submerged submarines or between a submarine and a surface vessel.

SONAR is Used for Underwater Communication.

SONAR is Used for Underwater Communication.

  • The military uses SONAR to track enemy warships or submarines.

  • It is used by fishermen for fish finding.

  • SONAR is used for seafloor mapping or seafloor imaging.

SONAR Seafloor Image

SONAR Seafloor Image

  • It is used in medical imaging to find cysts or cancer cells. This process is known as a sonogram.

  • Animals like dolphins, bats, toothed whales, etc., also use SONAR to communicate, detect any obstacle in their surroundings, and detect their prey. This ability in animals is called echolocation or biosonar.

Bats Use Sound Navigation to Detect their Prey

Bats Use Sound Navigation to Detect Their Prey.


SONAR is used because sound waves travel through the water much better than light waves or radar. Since submarines do not have windows, SONAR is a submerged submarine's eyes.