What does sonar mean?
Sonar is a method for finding objects and learning about their position by sending out sound waves and studying the echoes that return. The technique is most closely associated with ships, submarines, and underwater vehicles, but it is also used in fisheries, ocean research, geology, and industrial inspection. A sonar system may actively send a sound signal, or passively listen for sounds made by other objects. In everyday figurative use, the word can suggest searching for information that is concealed or difficult to detect. Sonar became especially important during the First World War, when underwater detection helped protect ships and submarines from one another. Its name is an acronym formed from “sound navigation ranging,” and today it remains a familiar term in maritime, military, scientific, and technological contexts.
nounSonar is a technique or system for detecting objects and determining their distance or direction by transmitting sound waves and analyzing the echoes they return. It is especially associated with underwater navigation, submarines, ships, and maritime research.
- The use of sound waves and their echoes to detect objects, especially underwater vessels, and to determine distance or direction.
"The submarine used sonar to track the approaching vessel through the dark water."
"The research vessel mapped the seabed with sonar."
"The crew heard an unexpected signal on the passive sonar."
Usually used in the singular for the general technique or system; the plural refers to multiple distinct sonar installations, devices, or systems.
"The fleet installed new sonars on several of its submarines."
The word sonar practically announces its own method: SOund NAvigation Ranging.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sonar come from?
Sonar was coined during the First World War as an acronym for “sound navigation ranging,” describing the use of sound waves to detect submerged vessels and determine their positions. The term later became a general name for underwater sound-detection equipment and the broader technique. Its components, “navigation” and “ranging,” reflect the original military purpose of locating vessels through acoustic signals.
How sonar is actually used
Usually a technical, military, nautical, or scientific term. In general use, it can also refer figuratively to a process that reveals hidden information or detects something difficult to see.
Easily confused with sonar
Sonar uses sound waves and their echoes, whereas radar uses radio waves and their reflected signals.