探たん信しん儀ぎ

noun

active sonar

Technical term for active sonar, used in maritime and naval contexts. Refers to equipment that emits sound pulses to detect objects underwater.

• 潜せん水すい艦かんは探たん信しん儀ぎを使つかって海かい底ていの地ち形けいを調しらべた。

  The submarine used active sonar to survey the seabed topography.