Magnetic navigation isn’t new, with the compass being one of the most widely used instruments of all time. Beyond simply pointing north, magnetic fields can be used for navigation. Scientists have shown that spiny lobsters are able to navigate home using only magnetic fields to guide them from as far away at 20 miles. Steel buildings cause consistent magnetic disturbances creating a magnetic fingerprint unique to a building. The magnetic sensor in newer phones is powerful enough to detect the highly magnetic iron within the steel structure of the building. This technology has been used 3,000 feet below the surface of the Earth to map mines, using only a smartphone.
The accuracy of the GPS sensor on a cellular phone will place someone around 20ft from the true location. The cellular GPS assist (GPS-A) will bring that accuracy down to about 10 feet. The accuracy of magnetic positioning is 5 feet. This level of accuracy didn’t require launching multi-million dollar satellites or installing a nationwide network of cellular towers. It was accomplished with a $199 Nexus 5X and nothing more. Using the phone’s compass chip and magnetometer, the building can be mapped in minutes. The process is done by simply by specifying points on the floor plan and walking along that route with a phone. The floor plan is then uploaded to the cloud and the process is complete.
Magnetic positioning doesn’t require additional infrastructure, such as the installation of wireless access points, the technology can be easily leveraged by hospitals, stadiums, and airports. Large indoor areas would require dozens or hundreds of WiFi, BlueTooth or other sensors to provide an accurate location as the device has to be in constant contact with multiple sensors to maintain accuracy. Those sensors will need power, maintenance, and replacement which are costs that are avoided with magnetic positioning. The magnetic fingerprint is only altered during major construction where steel beams are added or removed. The process of updating an area can be accomplished by a single person in less than a single day with only a cell phone.
Magnetic positioning is easy to deploy, more accurate than GPS, requires minimal infrastructure, and updates can be completed by a single person using only a cell phone.