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Working of Sonar

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Last updated date: 17th Jul 2024
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Introduction to Sonar Wave

Have you ever thought why the oceans and seas are so deep? How do we measure their depth? And how do we detect the various things that are in the oceans and sea? To understand that, we need to understand the concept of sonar.

Sonar can be defined as a technique or device for locating and detecting objects, especially underwater by making use of the sound waves which are sent out to be reflected by the objects. It is a technology that is efficiently used in the field of oceanography.

What is Sonar?

SONAR stands for “ Sound Navigation and  Ranging.”



Uses of Sonar

The following are the uses of SONAR which are discussed as follows:

  1. SONAR is used for the purpose of locating underwater hazards and mines for the purpose of achieving safe navigation.

  2. It is used for the purpose of seafloor imaging and seafloor mapping.

  3. It is used for finding fish by commercial fishermen.

  4. It is also used for the purpose of communicating between a submarine and a surface vessel.

  5. It is also being used in the field of medical imaging. In this high-frequency sound waves are subject to the bodies and the echos are recorded for creating the images called sonograms.

  6. It is also used as a depth finder in the oceans.

There are two types of SONAR basically:

  1. Active Sonar: In this, a pulse of sound is sent inside the water that hits the object and is reflected back. The distance in this is measured by the time which is taken by the waves to return back.

  2. Passive Sonar: The applications of this SONAR type are used mainly in receiving sounds of the water body to locate other ships and submarines.

How Depth of the Ocean is Measured Using Sonar 

The depth of the ocean can be measured by making use of SONAR. This is how it works:

SONAR works by sending out the sound waves and measuring how long it takes for the echo to return back.

How do Bats Make Sonar?

Bats use high frequency sound pulses emitted through their mouth or nose and listen for the echoes to achieve echolocation. The bat can assess the size, shape, and texture of things in its environment using this echo. This helps bats to find the directions in the environment and catch its prey.

Measuring the ocean using Sonar

Measuring the ocean using Sonar

Sonar Waves

SONAR makes use of sound waves to see in the water. It is useful in mapping and exploring the ocean because the sound waves travel farther in the water than light and radar waves.

A SONAR device sends pulses of the sound waves down through the water. When these pulses hit some objects like vegetation or the sea bottom, they get 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 come back. It measures the strength of the pulse returns. The harder the object will be the stronger the pulse will return.



Some Interesting Facts

  • Leonardo da Vince was the first user of passive SONAR in the year 1490 when he put a tube onto the water and listened. 

  • Paul Langevin was the first user of active SONAR. 

  • The word SONAR was created during the second world war as an acronym for Sound navigation and ranging.


SONAR is a technique or method which is efficiently used in the field of oceanography. It is of great importance to us in many different ways as we have discussed above. So we can say that the sonar technique is very vital in this contemporary epoch.

FAQs on Working of Sonar

1. What are the two types of sonar?

The two types of SONAR are Active SONAR and Passive SONAR. Active SONAR emits an acoustic pulse of sound or signal into the water. If an object is in the path of the sound pulse. The sound bounces off the object and returns the echo to the sonar transducer. By determining the time between the emission of the sound pulse and its reception, we can determine the range and orientation of the object. Whereas passive SONARS are only capable of detecting noise. They are also referred to as the listening SONARS. They only receive signals from ships, submarines, dolphins, or whales. They are not capable of transmitting their own pulses.

2. What are the main uses of sonar?

The main uses of SONAR include the following:

  1. It is used for in-depth sounding of the ocean.

  2. It is also used in doppler navigation as well.

  3. It is useful for the purpose of finding fish.

  4. It is helpful to the divers for acoustic locating.

  5. It is useful for locating underwater hazards to navigation.

  6. It is used for the estimation of the range and direction of arrival of objects such as submarines and vessels.

  7. It is also used for the purpose of seafloor imaging as well as seafloor mapping.

Uses of Sonar

3. Which kind of sonar do bats use?

Bats use echolocation to travel and discover insect meals. They generate ultrasonography, or sound waves at frequencies above human hearing. The things in the bats' habitat reflect the sound waves that the bats emit.