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The complex algorithm which bats employ to identify plants could make for the most advanced facial recognition software yet

This past week we happened to cover both dolphin echolocation and facial recognition. Today comes a report on a study that may bring the two concepts a little closer together. German researchers have devised a computer algorithm which is able to identify plant species using sonar echoes, in the same way bats are able to find fruit and insects. If the technology is one day sufficiently refined, it could ultimately be used for facial recognition.

Bats rely on echolocation to find their way around and to hunt prey and forage for fruit. In order better to understand how the bats identify which plants bear the fruit they prefer, the researchers at the University of Tübingen devised a software routine that could analyze the echo response time and frequency of sound waves reflected off isolated plants. Each presented a distinct signature, based on the size and number of branches and leaves. The team was able to achieve nearly 100 percent accuracy once the study was complete.

Not only will the findings be valuable for the science of bats and echolocation, but the applications for humans are potentially great as well. The distinct advantage of a sonar identification system over a visual-based system is that it would be able to operate in low light or total darkness.

In the past decade, navies have been roundly criticized for extensively testing active sonar due to its potentially detrimental affect on marine life. Military-grade active sonar sends out a powerfully loud low-frequency signal with a range anywhere from tens to hundreds of miles under water. The effect on whales has been well documented—it’s akin to you or I standing next to a jet engine without ear protection. The active sonar interferes with their ability to navigate, often stranding them in unfamiliar waters where they may be unable to find food and starve to death.

Fortunately for whales and other cetaceans (dolphins, porpoises) who use echolocation, an entirely different sonar technology may now prove to save these animals’ lives.

Fishing nets are estimated to kill upward of 300,000 cetaceans every year. The problem is the nets are too thin and amorphous for the animals to see with their sonar and so they get caught unintentionally. Now, a beacon used by the British Navy to mark mine fields has been miniaturized to the extent that it can be strung on to fishing nets to warn cetaceans to stay away. The device is a spherical plastic shell which acts like a satellite dish to amplify and reflect sonar waves. It is entirely passive (meaning it doesn’t transmit sound, only listens for it), which gives it a big advantage over battery-powered active-sonar equivalents which can be difficult to maintain. When a dolphin’s sonar hits it, the signal is sent back so that the animal knows something is ahead in the water and can swim to avoid it.

While the beacon is a promising technology, it does nothing to prevent the entanglement of cetaceans who do not use echolocation to navigate. For those animals, the only current recourse is better fishery management.

A device used by the British Navy to mark minefields has been repurposed to keep sonar-equipped marine animals out of fishing nets

Whales vs. warriors. That’s how one judge views the current debate over the Navy’s testing of high-powered sonar, which some scientists say has caused massive whale strandings and panicked behavior. The Navy argues that the tests are critical, and that high-frequency sonar is the best way to detect quiet enemy submarines.

The National Resources Defense Council sued the Navy to stop its latest round of testing, set to take place off the Southern California coast, and a federal appeals court sided with the Navy, granting a temporary go-ahead. One judge wrote that it’s a question of the safety of our whales vs. that of our warriors, but another noted that there’s no reason the Navy couldn’t take certain precautions during its testing to avoid hurting marine life. The fight isn’t over—another hearing is scheduled for November 5.

Via: LATimes