Predicting Floor-Level for 911 Calls with Recurrent Neural Networks and Smartphone Sensor Data
In cities with tall buildings, emergency responders need accurate floor-level location to find 911 callers quickly. We introduce a system to estimate a victim's floor-level via their mobile device's sensor data in a two-step process. First, we train a Recurrent Neural Network (RNN) using Long Short-Term Memory (LSTM) hidden units to determine when a smartphone enters or exits a building. Second, we use a barometer equipped smartphone to measure the change in barometric pressure from the entrance of the building to the victim's indoor location. Unlike impractical previous approaches, our system is the first that does not require the use of beacons, previous knowledge of the building infrastructure or knowledge of user behavior. We demonstrate real-world feasibility through 63 experiments across five different tall buildings throughout New York City. Our system predicted the correct floor-level within 2 floors with 90.5
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