Indoor location sensing using geo-magnetism

We present an indoor positioning system that measures location using disturbances of the Earth's magnetic field caused by structural steel elements in a building. The presence of these large steel members warps the geomagnetic field in a way that is spatially varying but temporally stable. To localize, we measure the magnetic field using an array of ecompasses and compare the measurement with a previously obtained magnetic map. We demonstrate accuracy within 1 meter 88% of the time in experiments in two buildings and across multiple floors within the buildings. We discuss several constraint techniques that can maintain accuracy as the sample space increases. Categories and Subject Description C.3 [Special-purpose and application-based systems]: Real-time and embedded system General Terms Measurement, Performance, Experimentation, Design. Keywords Positioning System, Indoor positioning system, Magnetic field, Magnetic fingerprint, Systems for location determination, Wearable compu...

• Type: Journal
• Year: 2011
• Where: MOBISYS
• Authors: Jaewoo Chung, Matt Donahoe, Chris Schmandt, Ig-Jae Kim, Pedram Razavai, Micaela Wiseman
• Keywords: Computer Networks, Constraint Techniques, Measurement Performance, MOBISYS 2011, Steel Elements