If you're navigating on a boat, every boat has it's own deviation chart. When you then use the compass you factor in variation (what the chart says the difference is between mag north and true north) and the personalized deviation chart for that boat.<p>To set this up, some guy comes down to the dock, takes your boat out, does a few 360's with known landmarks in site and compiles a table of how your boat's compass varies from standard magnetic north. Big things like the engine, generator, keel, etc will influence what your deviation chart looks like. Usually it's less than 4 degrees at each point of the compass IIRC.<p>So every place in the world has metal objects that create that place's own distinct deviation from where magnetic north should be. So perhaps that's what these guys are using. A known table of variation and then looking at the deviation.<p>What I wonder about is what happens when someone turns on a 12 amp vacuum cleaner, a monitor nearby goes into powersaving mode, someone moves their laptop or someone with their own cellphone walks past. These things emit magnetic fields, so I wonder how they've solved the problem of the local deviation changing constantly.
I have a small site dedicated to providing information about gps/cell phone tracking. As part of that, I've been doing a bit of reading about cell phone tracking capabilities.<p>It amazes me that we are turning our phones into better tracking systems than we've ever used on wild animals. Whether it's sound fingerprinting, gps, WiFi tracking, or now magnetic disturbance tracking, your phone's location services is getting so it can tell within a few feet where you are at all times. (By 2016 FCC regulations make it a requirement that all phones locate themselves within 100m or so)<p>This has amazing potential for startups. If your phone knows you are at the gym, it can start your workout routine. If you are at the library, it can decrease the ringer volume. Now with inter-building location ramping up, the opportunities will only increase.<p>On a related note, this information can be requested by law enforcement without a warrant. Last year cell carriers handled over a million such requests. <a href="http://www.nytimes.com/2012/07/09/us/cell-carriers-see-uptick-in-requests-to-aid-surveillance.html?_r=1&hp" rel="nofollow">http://www.nytimes.com/2012/07/09/us/cell-carriers-see-uptic...</a><p>People wearing little electronic devices that allow law enforcement to determine their position and travel patterns over any period of time just by filling out a form and without a warrant. If you had told me 20 years ago this is where we'd be, I would have called you a paranoid nut-job.
What happens if there are large items which move and cause changes in the localised magnetic field readings?<p>Things such as lifts, vehicles, regularly changing stock levels... Or are these all considered negligible?
It apparently needs the user to move to get a position lock.<p>This will not work well with the typical use case: user is in a shopping mall, needs to go to the bathroom, wonders where the closest one is and where he is, stops walking, opens his phone and starts the app.<p>Expected outcome: the app says "toilets are 50 meters to the right".<p>If the app now tells the user "I have no idea where you are. Please walk in a random direction in a straight line for 20 meters and I will try to find out, then tell you where you are and where the closest toilets are, which means that you might have walked in the wrong direction to begin with", the user is not really happy.
I really like this new approach to the positioning problem, especially since it doesn't require setting up wifi or shooting satellites into orbit.<p>Does anyone know why this couldn't be used for outside positioning, much like GPS? Is the information not detailed enough, or do we lack good enough sensors to detect the fine-grained differences especially given all the electromagnetic noise that modern cities for example create.<p>Edit: I just realized it's probably also because somebody would need to create a world-magnetic-field map, much like the street view cars driving all over the world.
Whoa :) This is very clever. I've been working on indoor positioning quite a long time already and might give this a try.
No WiFi -> no extra WiFi hardware costs -> widespread use<p>This technology might disrupt indoor advertisement.
I guess this would be a relatively relevant place to ask, does anyone know of an affordable technology that can be used for precision (inches) tracking of 8-36 items indoor or out? The caveat would be affordable. The use case would is BMX Racing. Scoring is still done by hand! I've looked into RFID tagging but the docs and manufacturer's specs are all over the place. Any ideas?
I just don't see indoor navigation as a huge problem to be solved. And this seems a phenomenally complicated solution to a small problem.<p>GPS works because <i>outside</i> is an enormous, unfamiliar place with tens of billions of destinations. Inside is small, relatively familiar, and even a large building has, at most, hundreds of destinations.<p>Just watching the demo, it's super cool and super intelligent. But it doesn't look like it can do direction - it can only tell direction after you've walked a certain distance. How will it cope with large magnetic things that move - eg Forklift trucks, vehicles, trolleys, wire cages etc.<p>I don't buy it. Ikea is the only potential place I could see this being of use, and there's no way anyone's going to bake in an extra sensor to a smartphone on the offchance. Look how slow adoption NFC has seen and that's a MASSIVE problem with multiple applications and a clear financial incentive.
How does this work? I understand if you know the true north and the magnetic north, you can get the difference, but I assume a compas only can measure one of them (the magnetic one). How do they determine the 'fault' in the signal with just 1 signal?
I always thought a reasonable solution to this problem was triangulating via wifi and bluetooth signal strength from access points of known location. I tried it as a weekend project a few years ago but random fading was a killer and I never got it to work that well. Seems like it should be possible though. Are there good reasons not to do it this way?
Seems similar to the technology demonstrated in this article [1]. However, it does seem that IndoorAtlas Ltd had a better opportunity recognition radar.<p>[1] <a href="http://www.newscientist.com/article/mg21328516.200-apps-glowing-arrows-guide-you-around-a-new-building.html" rel="nofollow">http://www.newscientist.com/article/mg21328516.200-apps-glow...</a>
With reservations --simply because I don't know their details-- I'll say that this is nothing new at all and it could be the makings of another case of patent abuse.<p>Local changes to the magnetic field have been used for quite some time for purposes such as oil exploration. I remember talking to an old geologist/oil man about twenty years ago as he went about locating candidate areas to explore based on these fluctuations. He explained that they'd use magnetometers to map out underground "cracks", deposits and other features. To go from that from generating local location data by overlaying a map of some sort (whether it is a building or something else) is nothing less than trivial.<p>If you have any experience sailing you may have also witnessed the effect of large sunken metallic objects on the compass. Again, you could "navigate" by these effects "Hey we must be passing over the SS-Sunken Ship".<p>Gotta love patents.
Given that mobile phones have wires and electricity then they are creating small magnetic waves which will impact others.
That all said this technolody is very suitable for underwater GPS were a GPS signal does not penetrate the water due to weakness and how bad radio travels thru water in general.<p>So given that I would have to questions if the military don't already use something very similiar in submarines. Lets say I'd be very supprised if this was not being already utilised in some form or another in that feild.
The big problem/timesink here is mapping.<p>Could this solved by combining the mapping process with the quadracopters that can autonomously fly through and map a building?