Echolocation For Your Cell Phone 73
sciencehabit writes "In a few years, an iPhone app may give you a 3D layout of a room as soon as you step into it. Researchers have developed an algorithm that spits out the shape and contours of complex structures (including Switzerland's Lausanne Cathedral) using data compiled from four randomly placed microphones. The technology, which relies on the same sort of echolocation bats and dolphins use to navigate, could be used to develop more realistic echoes in video games and virtual reality simulations and to eliminate the echo from phone calls."
It reminds me of GPS or radio telescope signals... (Score:4, Interesting)
I *gasp* read the actual document (http://www.pnas.org/content/early/2013/06/12/1221464110.full.pdf+html) and it sounds like some pretty complicated work. It relies on a bunch of separate microphones to listen in an absolutely silent room for the exact same noise and the echos of bounces. Since you know where the microphones are in relation to each other you can compute when the initial sound and echos hits each microphone and from there reverse construct where the sound must have originated and the echos tell you what it bounces of off.
The math is a bit beyond me after being out of university for so long, but it seem similar to transliteration using in GPS where thanks to very fast sensor readings you can figure out where you are in relation to a fixed signal. To compute the shape in the in a noisy environment I wonder if you can use a "known" sound where you could listen for only that and filter out the regular noise. Either way the computation involved would be impressive but maybe not for the elusive "5 years time" computer.
It would be cool to have something like this in my fishing boat where instead of a dot on the screen I could get something that tells me where the fish are and what kind too. :-)
Maybe you could arrange them in a golumb ruler layout to further speed up processing... *sigh* Making websites pays well, but I miss computers science.
Re:It reminds me of GPS or radio telescope signals (Score:5, Interesting)
It would be cool to have something like this in my fishing boat where instead of a dot on the screen I could get something that tells me where the fish are and what kind too. :-)
At what point do you stop cheating and start fishing? What's so wrong with having intuition about where the fish are? There are plenty of tell-tale signs that would give you clues to where the fish are hiding.
I admit, I don't boat fish because it's absolutely way too boring. I prefer walking up the mountain river, pickup up river stones to see what bugs are underneath. Maybe boat fishing is just too different an animal that my tactics would not adapt well, but I doubt it. With enough experience, I am positive I could do just as well with a contour map of the water's floor and my own two eyes as the guy with the expensive boat with all kinds of sonic weapons.
Recreational fishing should be low-tech. Having endless gadgets to push the odds ever in your favor defeats the purpose.
Re:It reminds me of GPS or radio telescope signals (Score:4, Interesting)
I start to care when I find their trash littered all over the forest. I start to care when their loud boats zoom right into my casting line in the inlet. I start to care when their efficiency affect the experience for everyone else.
But all of that is besides the point. Recreational fishing is a meditative thing. You do it on the weekends, or for a couple weeks at a time, so that you can escape the daily grind and restore part of your soul. The more machines you add to that experience... you know the rest.