This is a picture of a sound mirror on the escarpment north of the Dungeness peninsular in the south of England. These were built in the years before the invention of Radar and were used to amplify the sound of incoming aircraft and thereby provide an early warning system in the event of attack. The acoustic mirror programme was the brainchild of Dr William Sansome Tucker but was quickly abandoned once radar had been proved as a workable concept.
There are several different types of sound mirror around this area and many have been preserved because Dr Tucker ignored official orders to destroy them.
Interesting pic. I had seen pics of the semi-circular designs but not this shape. It's a reminder that sound and infra-red were once seen as potential competitors to radar in the early days.ReplyDelete
There was an interesting segment in the first episode of the TV series "Coast" when they looked at some of these sound mirrors. They conducted an experiment using a period aircraft and some electronic listening equipment set up to 'receive' the sound focused by the mirrors. The noise of the aircraft was clearly heard several minutes before it could be detected with the ear alone.ReplyDelete
Interesting post - thanks for the info.ReplyDelete
I was aware that these had once existed, I'd seen photos. But was not aware that they were still in place.
There is a listing of the different sound mirrors and their designs at http://www.andrewgrantham.co.uk/soundmirrors/ReplyDelete