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Seawater is often turbid, clouded with organic matter and reducing visibility to mere feet. A new concept in underwater detection takes its inspiration from seals. These mammals have no problem finding fast-moving fish there, detecting food in murky water using their whiskers. An object moving through water leaves a series of miniature whirlpools in its wake. And that is what seals, using their whiskers, follow, according to economist.com.
A research led by Prof. Michael Triantafyllou from MIT is using the seal whisker as a model for developing an underwater sensor. If the scientists replicate the method using modern technology, they will be able to develop novel underwater sensors that could make submarines much more detectable, and greatly increase the ability of ships, aircraft, and submarines to detect enemy subs underwater.
Current methods to detect objects underwater include active sonar, which involves sending out a pulse of sound and detecting objects based on the return “echo” of the pulse. The problem is that it reveals the user’s location. The other method, passive sonar, merely listens for the acoustic sign of enemy ships. The downside is if an adversary is very quiet there may be little or nothing to listen to.
“Whisker technology” is also a passive detection method: a seal simply “feels” the ocean currents for signs prey are nearby.
Even at a full stop a large, several thousand ton submarine is likely producing minute vortices, as current swirls past the boat’s contours. These vortices may end up being detectable. Furthermore, vortices linger in the water column for minutes or even hours, much longer than sound.
The next step will be to make a high tech analog that doesn’t involve using a seal’s whiskers, facial nerve endings, and brain.
As many nations put nuclear-tipped missiles to sea on subs meant to stay hidden and evade enemy detection, these underwater vessels may now be easier to detect, thanks to the whisker technology, according to popularmechanics.com.
It remains to see whether the new tech could represent a major breakthrough that threatens the ability of submarines to operate underwater, or it could become a sensor tech that complements, not replaces sonar.