History: Sound location equipment in Germany, 1939. It was used to determine the direction and the elevation of the aircraft. [617x800]

https://i.redd.it/gxqadi9px1ky.jpg via /r/HistoryPorn https://www.reddit.com/r/HistoryPorn/comments/5y3hz2/sound_location_equipment_in_germany_1939_it_was/?utm_source=ifttt