Experimental acoustic sound mirrors 20' 30' 200' forerunner of radar provide early warning incoming enemy aeroplanes airships 1916 - 1930s ww1 ww2

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Size: 4912px × 7360px
Location: Denge, Dungeness, Romney Marsh, Kent, UK
Photo credit: © Yon Marsh / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: 20, 30, 200, 1916, 1930, acoustic, aeroplanes, airships, block, bug, bugging, collector, concave, concrete, device, disk, dungenes, ears, enemy, experimental, incoming, listening, microphone, mirror, mirrors, nature, observe, observing, parabolic, prying, radar, reflection, reflector, reserve, security, sound, spying, surveillance, voyeurism, wall, war, weapon, wiretapping, ww1, ww2, wwi, wwii, zeppelin