Somehow, our options are quite limited when it comes to finding our way around the ocean. While the GPS is fine if you skip the surface of the water, it becomes useless at depths of only one foot (30 cm). Scientists demand a new advance in the world of underwater navigation, inspired by marine animals that use polarizing light in ingenious ways.
"We study marine animals because we believe that some species may be using the polarization of light to navigate, and our new study is a proof of concept that this is possible," says Dr. Samuel Powell, a researcher at the University from Queensland in Australia and member of the research team.
While marine animals such as squid, shrimp, cuttlefish and octopus were already known to use polarized light to communicate, humans are not able to lift it without using specialized lenses, such as those used in glasses of polarized sun These creatures can not only detect it, but reflect it to reveal its presence to aggressive competitors.
So Powell and his colleagues suspected that creatures could also use light to navigate, and they built an imaging system equipped with polarization sensors to explore the possibilities. These sensors depend on the transmission of light and scatter through the water, and use these patterns to calculate the position of the sun in the sky. In turn, this makes the system can be used as a compass and for geolocation purposes.
"At present, submarines use GPS systems on the surface, and when they descend they rely on uncertain calculations to calculate their position," says Powell. . "The error in this case has no limits, that is, the longer without GPS, the more wrong your calculation can be."
The team tested the new system in different underwater locations around the world, at different depths and times of the day. The researchers say that the first data suggest that the margin of error for their geolocation system is six meters (20 feet) for each kilometer traveled (0.62 miles). While still in their proof-of-concept stage, researchers believe that with further development the technique could allow navigation to depths of up to 200 m (656 ft) for sustained periods of time.
"Using polarization sensors, our method would allow real-time underwater geolocation with more accurate long-distance results, without the need to periodically resurface," says Powell.
The research was published in the journal Science Advances.
Source: University of Queensland