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.
Introduction:
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 >>.

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.
RADAR Tutorial RELATED LINKS
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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