Scientists have perfected a new technology that can transform a fibre optic cable into a highly sensitive microphone capable of detecting a single footstep from up to 40km away.
Guards at listening posts protecting remote sensitive sites from attackers such as terrorists or environmental saboteurs can eavesdrop across huge tracts of territory using the new system which has been created to beef up security around national borders, railway networks, airports and vital oil and gas pipelines.
Devised by QinetiQ, the privatised Defence Evaluation and Research Agency (DERA), the technology piggybacks on the existing fibre optic communication cable network, millions of miles of which have been laid across.
At present, the microphones are not able to pick up the sound of human speech. right:] (more)
Mason & Hanger and two other companies had similar products about 15 years ago. It had a switchable filter (10 Hz to 1 kHz / no filtering) and a headphone jack.
