How does a Submarine Sonars work?
The early sonars, invented by the English the help with North Atlantic Convoys during the second world war, were called ASDIC and that meant it was named after the Anti-Submarine Detection Investigation Committee. And the pings were really that loud, not movie magic. The “ping” was a high pitched high frequency sound wave, which carries in water much better than through the air (which is why there is no airbourn Sonar. This sound is carried to the object or the sea bed, knowing the frequency of the sound determins how fast it travels through the water, this gives a distance from the sea bed, any early returns of the “ping” would mean an object is above the sea bed, maybe a whale orr a submarine. In the early days this would have been backed up by a device rather like an ear trumpet which would be in the water, by turning the trumpet towards the object you could determine if it was man made or natural, ie does it have an engine sound, you can also fix a bearing on the object in this way
