Towards Commercially Applicable Indoor Positioning on Smartphones through Geomagnetic Sensing

Indoor positioning solutions attempt to extend location-based services to indoor environments where typical outdoor positioning solutions are not applicable. Current mainstream indoor positioning solutions rely on extra devices such as WiFi APs and iBeacons. These solutions involve a non-trivial cost of installing and managing. To avoid such non-trivial cost, infrastructure-free geomagnetic based techniques have been proposed, however, only practically verified in limited indoor environments. In this study, we present our commercially adopted end-to-end geomagnetic sensing based solution including a cost-effective measurement methodology to collect geomagnetic field signals, an online calibration technique to address sensor distortion and diversity issues, and an online motion identification technique to resolve issues of motion dynamics. According to the results carried out in 120 shopping malls, our solution's error distance is persistently within 5m.