Indoor navigation on your smartphone, using the Earth’s magnetic field — just like a pigeon

Researchers from the University of Oulu in Finland has created anindoor positioning system (IPS) that uses the Earth’s innate magnetic field to ascertain your position — just like a homing pigeon or spiny lobster. According to IndoorAtlas, the company spun off by the university to market and sell the tech, its system has an accuracy of between 0.1 and 2 meters.

The Finnish IPS technology is ingenious in its simplicity. Basically, every square inch of Earth emits a magnetic field — and this field is then modulated by man-made concrete and steel structures. If you have a map of these magnetic fields, and a magnetometer (compass), accurate navigation is very simple indeed — and all you need to make a magnetic field map, or to navigate one, is a modern smartphone (demo video embedded below).

Almost every smartphone has a built-in magnetometer, just so your phone knows which direction you’re facing in — but this sensor is apparently sensitive enough to create magnetic field maps that have an accuracy of 10 centimeters. Creating a map is as simple as drawing out a floor plan, and then walking around a location (a shopping mall) so that the magnetometer can build up a map of your surroundings — both using apps provided by IndoorAtlas. Then, if you’re visiting an area that has a magnetic field map, you run the IndoorAtlas service… and off you go! There is an also an API, if developers want to create apps that react to your movements — if McDonalds wants to create an app that pops up a special offer on your screen when you’re outside McDonalds, for example.

When you look at most other IPS systems, which require you to blanket a venue with thousands of WiFi or Bluetooth base stations, the IndoorAtlas solution — which requires no extra infrastructure — is incredibly exciting. Imagine something like the London Underground or New York subway — providing an active IPS system in such places would be invaluable to tourists, and increase throughput significantly, but using WiFi or Bluetooth is unfeasible. Ditto huge airports, hospitals, and underground parking lots. IndoorAtlas could even be used by miners, or potholers/cavers.

Now, before we all go out and buy stock in IndoorAtlas, I should point out a gaping issue that the company seems to ignore (but which it surely knows about): Magnetic fields change. As the molten iron in the Earth’s crust shifts, so does the magnetic field. This shift is fairly slow — but even so, it still means the World Magnetic Model has to be updated every five years. Second, and perhaps more importantly, what about the effect of objects that aren’t part of the original magnetic field map, such as cars, moving lifts, and electric motors? Who knows, though — perhaps the effect of these objects is negligible.

If you’re an app developer, or you want to bring IPS to your mall/airport/subway, go ahead and contact IndoorAtlas.

Read more about the awesome applications of Indoor Positioning Systems

Indoor navigation on your smartphone, using the Earth’s magnetic field — just like a pigeon