Passive sonar on modern submarines can only measure direction not range

Modern submarine passive sonar can only measure direction but not range is not true. Passive sonar can measure both direction and range, but the range is short. In practice, the traditional target motion analysis method is still often used. By recording the direction of motion of the boat and the target over a period of time, the distance to the target is calculated using trigonometric functions. The outboard array can listen to about 120-160° range on both sides, but there is still a blind spot in the direction of the stern.

Passive sonar detection principle

Passive sonar, also known as noise sonar, it is through the acceptance and processing of radiated noise or sonar signals emitted by the target in the water, the submarine detection and positioning of the enemy's targets in the past a way to ambush the enemy's underwater targets, usually stationary silent state, usually in a number of complicated sea conditions in the waterway Or throat channel to take a wait-and-see hit on the go, in the enemy fleet to react to, has slipped away.

Passive sonar system has not adapted to the requirements of modern naval warfare, early Amoy _, now using the active and passive dual circuit sonar, attacking the opening of the active and passive sonar system to search for enemy targets, to avoid enemy attacks when the closure of the active sonar, the opening of the passive sonar to locate the enemy position waiting for an opportunity to attack the enemy's mode of operation.