What are sonars used for?

Sonar uses sound waves to ‘see’ in the water. NOAA scientists primarily use sonar to develop nautical charts, locate underwater hazards to navigation, search for and map objects on the seafloor such as shipwrecks, and map the seafloor itself. There are two types of sonar—active and passive.

Does sonar kill fish?

The military’s use of sonar poses no threat to fish, a new study suggests. The study was designed to explore the effects of Navy ship sonar on fish swimming nearby. Investigators found no damage to the fish’s inner ears after they underwent intense sonar exposure, even several days afterward.

How does sonar work in the deep ocean?

Sonar works well if the submarine has a highly reflective steel surface and is surrounded by water at a constant temperature. But in the deep ocean the water temperature varies, which causes the water density to vary. This changing density creates an effect called the thermocline, which acts as a barrier, causing sound energy to bend away.

Is sonar used to hunt submarines?

While sonar is well known, it’s rarely actually used to hunt submarines as it’s too easy to hide from the incoming sound waves. Instead modern anti-submarine warfare systems are actually extremely sensitive listening devices which rely on the submarine giving away its position by the sounds it makes. This is known as passive sonar.

What are the two types of sonar technology?

Two types of technology share the name “sonar”: passive sonar is essentially listening for the sound made by vessels; active sonar is emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of “targets” in the water.

Can submarines be detected by sound?

Submarines generate sound from their machinery and crew, and sound waves from other submarines or surface ships are used to find them. But of course submarines don’t want to be found. With the Swedish Navy currently hunting what is believed to be a Russian mini-submarine in Swedish Baltic waters, how can unseen boats below the water be detected?