U.K. marketCat's eyes locate things underwater

Published 20 March 2008

A new underwater cat’s eye can reflect back a tuned signal, revealing its location, to existing sonar systems; new device does not use batteries — and it does rely on toxic chlorofluorocarbons (CFCs)

Always learn from Mother Nature: A nautical version of cat’s eyes developed by U.K. defense scientists to mark and find underwater locations could also be used to locate oil fields or transatlantic cables. It could also help to avoid dolphins and whales being caught up in fishing nets. Scientists from the Defense Science and Technology Laboratory (DSTL) have successfully shown in sea trials that the new underwater cat’s eye can reflect back a tuned signal, revealing its location, to existing sonar systems (for example, those mounted on maritime vessels).

Whales and dolphins also use sonar to navigate, so if the cat’s eye was attached to fishing net, they would be able to pick up the signal and avoid the area. To date, battery-powered sonar location devices have been used by oil and cable companies which continually pulse a signal back to a sonar system. The new cat’s eye, however, is a passive system, meaning that it only sends a signal when sonar tries to identify it. Another downside to using battery powered devices is that they need periodical replacement before the battery runs out. This results in significant maintenance costs, and if the battery power has died, then the devices themselves could be lost forever. The new cat’s eye does not use battery power.

Historically, passive devices have relied on toxic chlorofluorocarbons (CFCs) housed in metal disks to bounce the sound back. The new environmentally friendly cat’s eye system does not require CFCs as its physical properties alone are powerful enough to send a signal back to the sonar. “This is another example of DSTL technology being directed outside its original military application and making a difference to industry,’ said David Harris, head of technology transfer.

Subsea Asset Location Technologies has been setup specifically to commercialize the development of the technology.