Which type of sonar is typically used in military applications for detecting submarines?

Active sonar is typically used in military applications for detecting submarines because it involves emitting sound waves into the water and listening for the echoes that bounce back from objects, such as submarines. This method allows for the active determination of an object's location, distance, and speed because the system analyzes the time it takes for the sound waves to return after striking the submarine's hull.

Military forces utilize active sonar in various operational scenarios, such as anti-submarine warfare, where the need for precise targeting is crucial. By sending out sound pulses and interpreting the delay in their return, active sonar systems can provide real-time situational awareness and can effectively identify and track hostile submarines.

In contrast, dipping sonar refers to systems that are lowered into the water from a helicopter or aircraft, which while useful, may not be as advantageous in all military contexts as it depends on proximity and specific operational conditions. Passive sonar, on the other hand, listens for sounds made by submarines without emitting its own signals, which can be stealthier but relies on the submarines being active. Ultrasound is a technology more commonly associated with medical imaging and other civilian applications, rather than military submarine detection.