Re:Concrete blocks that once protected Britain
by londons_explore on Monday January 07, 2019 @05:37AM
(#18844186)
Accoustic mirrors could actually be rather effective - a large mirror could perhaps hear a plane in good conditions up to 75 miles away, well over the horizon.
Early radar only had about the same range, but the advantage was it could work in nearly all conditions, rather than just windless sunny days.
They also weren't used by the Germans, so perhaps the accoustic mirrors were as much of a secret as radar.
Early radar only had about the same range, but the advantage was it could work in nearly all conditions, rather than just windless sunny days.
They also weren't used by the Germans, so perhaps the accoustic mirrors were as much of a secret as radar.