MIT Researchers Develop Underwater Navigation System To Map Ocean Floor
Some experts believe that as much as 80% of the world’s oceans remain completely unexplored. Others say, despite three quarters of the world’s surface being covered in water, it’s easier to explore space than it is the ocean floor.
A new project from a team of researchers at MIT is looking to solve that problem, by creating a navigation system that works even when you’re hundreds of metres underwater.
Rather than using GPS, which becomes more or less useless in ocean exploration due to the way radio waves scatter in water, most existing underwater navigation systems use sonar. The problem is, sonar uses up a lot of energy, way too much for batteries to cope with, especially in the murky depths of the ocean.
Research scientist Reza Ghaffarivardavagh neatly summarised the problem to MIT News, saying:
Why can’t we send out unmanned underwater vehicles on a mission to explore the ocean? The answer is: We will lose them.
However, a new system called Underwater Backscatter Localisation aims to resolve that issue by using sound itself, instead of batteries, to power the navigation system. The device works by using ‘piezoelectric materials’ which generate an electrical charge when subjected to sound waves.
The piezoelectric materials selectively reflect sound waves to create a binary signal used to generate a location fix, all the while being powered by the sound waves.
Sound complicated? That’s because it is. The MIT team say that this method is tricky to get a hang of, especially when used in shallower waters where signals can more easily rebound off the ocean floor.
The researchers recently presented the idea in a paper published for the Association of Computing Machinery, and have also developed a proof-of-concept version of the UBL system, which works at distances of up to 50 centimetres.
Going forward, the team are working on increasing the range of the system. They say the device could be used for everything from marine conservation to aquafarming, with the ultimate goal being to create a navigation system suitable for autonomous vehicles used to map large swathes of the ocean floor.
If you have a story you want to tell, send it to UNILAD via [email protected]