What is one way passive sonar systems operate?

Passive sonar systems operate primarily by listening for noises made by submarines and other underwater objects. Unlike active sonar, which emits sound waves and waits for their echoes to bounce back in order to detect objects, passive sonar relies on the detection of sounds that are naturally produced by submarines, such as engine noise, propeller cavitation, and machinery sounds.

This listening technique allows passive sonar to gather information about the presence and movement of submarines without revealing its own location, providing a stealth advantage. By analyzing these sounds, operators can determine various factors such as the type of submarine, its speed, and its course.

In contrast, other methods mentioned, such as emitting sounds to locate submarines, sending visual signals to other ships, or measuring magnetic fields, are not characteristics of passive sonar. They either involve active techniques or utilize different technologies altogether.