Currently being developed by Australian tech firm Optus, the buoy is anchored to a seabed-located box, that emits sonar signals into the surrounding water. A processor in the buoy analyzes the reflections of those signals, and is able to identify the sonar signature of shark-sized objects in the vicinity. To lessen the chances of it being fooled by animals like dolphins, it also takes note of how such objects propel themselves through the water, to see if they’re moving in a shark-like fashion.
The idea is that a series of the buoys/boxes could be arranged in a row offshore, running parallel to a beach. Whenever any of them detected a shark, it would send an alert via satellite to the local lifeguard’s smartphone. That person would then sound an alarm, telling all swimmers to get out of the water until the shark had moved on.
via Gizmag
