Fibre optics to detect sound of terror

Scientific breakthrough will use global cable network to protect oil and gas pipelines – and politicians

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.

Trials have already been staged in Europe to use the OptaSense system, which evolved out of military sonar and submarine technology, on railways to prevent vandals or thieves trespassing on high-speed lines as well as to counter terrorism. It has been deployed by several blue chip oil companies to protect energy pipelines which run through some of the most lawless and remote regions of the world.

Oil and gas companies lose millions of pounds each year through “hot tapping” in which thieves siphon off oil to sell. The process can be dangerous, resulting in explosions which have claimed hundreds of lives as well as causing serious environmental damage. Its creators say the system can also safeguard against accidental damage caused by builders and farmers working close to pipelines in Europe and North America. But it is hoped the technology will be rolled out to enhance security arrangements at prestige sites, among them Heathrow’s Terminal 5 or the Olympic Games and to protect major gatherings of world leaders such as during the G8, which has become an increasing magnet for protest movements.

The system works by picking up tiny seismic waves detected under the ground by the fibre optic cable which carries an optical pulse sent from a central computer. Virtual “microphones” created remotely every 10 metres along the cable register the vibrations through the ground. The patterns caused by the disturbances are then matched to digitally pre-sampled sounds such as footsteps, cars or diggers and the information fed back to a command centre where security personnel are able to deploy drones or even armed response teams to check out the threat.

The system is sensitive enough to detect sounds 40km away, along the line of the cable. It can also pick up sounds perpendicular to the cable: the sound of someone approaching on foot 30 metres away or a vehicle 50 metres away.

At present, the microphones are not able to pick up the sound of human speech. Magnus McEwen-King, managing director of OptaSense, said: “We take a standard telecoms cable and, without changing its structure, install our technology to create thousands of virtual microphones along the length of the cable.

“What you get is an intelligent hearing device, buried underground, which can monitor borders, perimeters or property for intruders. Optasense not only detects but identifies an approaching threat and alerts you to the location so that you can take necessary action to prevent intentional or accidental damage.

“People are amazed when they see that it can be configured to tell different types of vehicles apart… or tell if a person is walking or running towards the area you are monitoring.”