Navigation security

POSYDON – DARPA’s Underwater GPS

GPS – what would we do without it? It can let you know how to get to a new friend’s house, help navigate an unknown country, and even direct a missile to its target. One thing GPS can’t do is penetrate to the deep reaches of the ocean. Soon enough, though, the seas may have their own positioning system, if the US Defence Advanced Research Projects Agency (DARPA) gets its way.

GPS works by broadcasting microwave signals from a constellation of satellites orbiting the Earth. Barring obstructions like tall buildings and mountains, these signals can reach pretty much anywhere on the surface of the planet, but anywhere underwater is pretty much impenetrable for them. Sure, submarines could always surface to get some quick positioning, but this poses its own risks, especially when operating in hostile waters.

DARPA is now working with BAE Systems and not-for-profit company Draper to develop an underwater GPS-like system called the Positioning System for Deep Ocean Navigation (POSYDON).