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This study explores indoor location sensing using geo-magnetism to create unique magnetic field signatures for positioning systems. The system overview, evaluation, conclusion, and discussion highlight the efficiency and challenges of this innovative approach.
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MobiSys 2011 Indoor Location Sensing Using Geo-Magnetism JaewooChung, Matt Donahoe, Chris Schmandt, Ig-Jae Kim, PedramRazavai, MicaelaWiseman -Twohsien 2011.10.31
OUTLINE • Introduction • System overview • Evaluation • Conclusion • Discussion
OUTLINE • Introduction • System overview • Evaluation • Conclusion • Discussion
INTRODUCTION • Disturbance of the Earth’s magnetic field • Steel and concrete skeletons Fingerprint!!
INTRODUCTION • Scope of this work • Characteristics of magnetic field signatures • Performance of positioning system • Reducing outliers
OUTLINE • Introduction • System overview • Evaluation • Conclusion • Discussion
SYSTEM OVERVIEW • The observed characteristics of indoor magnetic fields • E-compass HMC6343 • Stepper motor
SYSTEM OVERVIEW • RMS difference
OUTLINE • Introduction • System overview • Evaluation • Conclusion • Discussion
EVALUATION • Wearable device
EVALUATION • Test sites
EVALUATION • Result of performance
EVALUATION • Result of performance
EVALUATION • 75.7% < 1m
EVALUATION • vectors
EVALUATION • Modified algorithm • Varying the search space from the last known position • Filtering the predicted position by adding conditions in our algorithm
EVALUATION 86% < 1m 88% < 1m
EVALUATION • Different floor
EVALUATION • Long term performance
EVALUATION • Effects near moving objects
OUTLINE • Introduction • System overview • Evaluation • Conclusion • Discussion
OUTLINE • Introduction • System overview • Evaluation • Conclusion • Discussion
DISCUSSION • Advantage: • no infrastructure overhead • Disadvantage: • Outlier could be placed at any location • Error increases with the size of map • Effort and time required