Underwater GPS Inspired by Shrimp Eyes

A diving trip to the Great Barrier Reef may have unlocked a new way to build a GPS-like sensor that works underwater. The device is based on recent scientific understanding of how marine animals sense their geolocation based on the signature polarization patterns of light entering the water. A few years ago, U.S. and Australian researchers developed a special camera inspired by the eyes of mantis shrimp that can see the polarization patterns of light waves, which resemble those in a rope being waved up and down. That means the bio-inspired camera can detect how light polarization patterns change once the light enters the water and gets deflected or scattered. Those researchers now realize that they can use those underwater polarization patterns to deduce the sun's position--and use that to figure out the location of the camera itself.