Variable depth sonar

Variable depth sonar is found on most modem anti-submarine warfare vessels. As the name indicates, the device can be suspended below die hull. Fixed-bow sonar is used for long-range detection/location, and one such device has detected a submarine at ranges in excess of 2000 miles... 

Variable Depth Sonar Similar to a towed array, but a variable depth sonar has a motorized fish at the end of the array to permit the array to... 

The ship s sonar provides submarine position data to a predictor which computes mortar aiming position. The triple-barrelled mortar fires a pattern of three mortar bombs which are programmed to give a three dimensional expl pattern ahead of the target. The bombs can be set to expld at variable depths using hydrostatic fuzes, and are also fitted with delayed action fuzes... 

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