Going Deeper Underground: Using accelerometers on mobile devices to enable positioning on underground public transportation systems

Abstract

Thanks to rapid advances in technologies like GPS and WiFi positioning, smartphone users are now able to determine their location almost anywhere they go. This is not true, however, of people who are travelling in underground public transportation networks, one of the few types of high-traffic areas where smartphones do not have access to accurate position information. In this thesis, we introduce the problem of underground transport positioning on smartphones and present SubwayPS, an accelerometer-based positioning technique that allows smartphones to determine their location substantially better than baseline approaches, even deep beneath city streets. We highlight several immediate applications of positioning in subway networks in domains ranging from mobile advertising to mobile maps and present MetroNavigator, a proof-of-concept smartphone and smartwatch application that notifies users of upcoming points-of-interest and alerts them when it is time to get ready to exit the train.