Indoor Trajectory Estimation with Passerby Data without GPS nor WiFi Signals

There has been an increasing need to log user location trajectories in indoor environments. Managers of commercial facilities need to obtain a complete set of location trajectories of visitors who remain in the facilities for marketing and congestion control in a cost-effective and privacy-preserving manner. We propose an innovative technique called symbiosis indoor location tracking (SILT) for constructing user trajectories. SILT can estimate the location trajectories of users without using the Global Positioning System (GPS) and WiFi by relying on other users’ activities when visiting facilities located on a map and on evidence indicating the co-existence of nearby users through detected Bluetooth Low Energy signals. Simulation and field-study experiments in indoor environments demonstrated the potential of SILT to balance efficiency and accuracy in indoor location logging using only limited passerby data without requiring GPS and WiFi signals or prior calibration operation.