Indoor navigation has long been one of the toughest problems in mobile — GPS satellites are prone to failure when users are underneath more than a few inches of roofing, and there are precious few other ways of reliably determining a device's position. But this is precisely the problem that Finnish startup IndoorAtlas claims to have solved.

A spinoff from research at the University of Oulu, IndoorAtlas' upcoming app uses the built-in compass found in most modern smartphones to detect changes in the earth's natural magnetic field — the same technique used by homing pigeons. These tiny alterations correspond to the position of man-made objects such as desks and shelves, as well as a building's fundamental materials, allowing users to reliably navigate around pre-prepared floor plans without the need for GPS or other positioning systems.

The company claims that its technology provides accuracy of up to 10 centimeters, easily enough to navigate in most public places. With a recently-launched API program, it's opening up its so-called Indoor Positioning System (IPS) to select third-party developers, with the aim of creating an ecosystem around the technology before its public release. Check out an early-stage demonstration of IndoorAtlas in the video below.