Major oil companies are relying on a new fiber-optic technology to keep an underground ear on intruders, the Independent reports. Devised by a British defense firm, the OptaSense system consists of microphones placed along sensitive fiber-optic cables already laid underground. The cables sense vibrations, the mics pick it up, and OptaSense compares the signals with other sound samples to identify what's afoot.
Created to improve security at airports, borders, and major world events like the Olympic Games or G8 summit, OptaSense can parse signals up to 25 miles away. "What you get is an intelligent hearing device, buried underground," says a director of the project. "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."