Active Sonar vs Passive Sonar | difference between Active Sonar and Passive Sonar

This page compares Active Sonar vs Passive Sonar and mentions difference between Active Sonar and Passive Sonar.

Sonar system uses sound waves to detect and consecutively locate the objects underwater. It is very useful to detect submerged objects and also to measure its distance. Active sonar picks up echo of its own transmitted sound waves where as Passive sonar picks up noise made by others (equipments, propellers, mammals) using electronic means.

Active Sonar

Following are the features of Active Sonar system.
• It consists of transmitter and receiver both.
• Active sonar transmits sound waves towards the object and receives reflected waves from it. Active Sonar sounds are emitted in pulse forms and it listens for the echo after transmission.
• The reflected waves are used to detect the object and measure its distance.
• As active sonar transmits sound waves in the sea, it is considered to be harmful for the marine life.
• Active sonar has capability to detect vessels which are quiet and are difficult to be detected by passive sonar as explained below.
• Active sonar can detect marine mammals in shipping lanes or in high sound pressure zones.
• Refer advantages and disadvantages of Sonar >>.

Active SONAR vs Passive SONAR

Passive Sonar

Following are the features of Passive Sonar system.
• It consists of receiver part only.
• It does not transmit sound waves but receives sound waves emitted by sea animals used for communication. It also receives other vibrations. Basically passive sonar is used for detection of noise made by others (engines, propellers, animals etc.).
• Passive Sonar keeps large sonic database. Moreover sonar operator classifies signals by use of computer and uses stored databases in order to identify classes of ships and take action accordingly.
• As it does not transmit waves, it is considered to be safe for sea animals compare to active sonar type.


Refer following radar tutorial links which covers radar measurements, doppler radar, FMCW radar, radar bands, radar scope, weather radar, radar range and resolution, ground radar etc.
RADAR tutorial   Radar Measurements   Doppler Radar   FMCW RADAR   RADAR BANDs   RADAR SCOPE   Weather Radar   Ground Penetrating Radar System  RADAR RANGE and RESOLUTION 

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