Magnetic fields trump Wi-Fi for better LBS accuracy

August 07, 2012

Location-based services have always had problems with indoor accuracy, as GPS only works when you’re outside where the satellites can see you. Finnish company IndoorAtlas says the solution may be all around you. Literally.

Wi-Fi has been touted by companies like Google, Navizon and Skyhook Wireless as a handy supplemental technology for indoor location tracking. But it requires blanket Wi-Fi coverage, as well as constant updates to ensure the mapping software matches real-world AP deployments. And it requires that the handset’s Wi-Fi be switched on, which can raise battery life issues (although Skyhook and Navizon say their latest solutions allow development of apps that have minimal impact on battery life).
IndoorAtlas has a unique solution to indoor tracking – instead of using radios, it measures disturbances in the Earth’s magnetic fields created by a building’s internal structures.
According to the company’s white paper on “ambient magnetic field-based indoor location technology” [PDF], the core technology is completely software-based and only requires a smartphone with built-in sensors. It also requires a magnetic field map to be generated for the part of the building where the location service is going to be used:
The application uses the IndoorAtlas API to communicate with the location service. The API sends processed sensor data to the location service, which computes the current location estimate and delivers the estimate back to the application's event listener method through the API.

The location service connects to the map database, which hosts the magnetic field data collected from the building using the IndoorAtlas Map Creator application. The IndoorAtlas location service has been built on the top of Microsoft's Windows Azure cloud platform.
IndoorAtlas says its software can deliver location accuracy “from 0.1 meter to 2 meters” – which, if it works as advertised, is a vast improvement on Wi-Fi positioning technology, which currently promises accuracy of 10 meters (which is roughly equivalent to GPS, incidentally).
Interestingly, IndoorAtlas says they got the idea of using the Earth’s magnetic field from spiny lobsters:
Some animals, such as spiny lobsters, are not only able to detect the direction of the Earth's magnetic field they can even sense their true position relative to their destination. This means these particular animals are able to derive positional information from local cues that arise from the local anomalies of the Earth's magnetic field.
IndoorAtlas is currently seeking developers around the world interested in mapping buildings, supplying floor plans or evaluating its software in exchange for early access to its technology, reports entrepreneur blog SpringWise.
Thumbail image from server side store: 
John C. Tanner