# SubwayPS: Towards Enabling Smartphone Positioning in Underground Public Transportation Systems

## TL;DR

SubwayPS introduces an accelerometer-based method enabling smartphones to accurately determine their location in underground transit systems, addressing a key gap in positioning technology for subterranean environments.

## Contribution

The paper presents SubwayPS, a novel accelerometer-based positioning technique that significantly improves underground smartphone location accuracy over baseline methods.

## Key findings

- SubwayPS outperforms baseline approaches in underground positioning accuracy.
- The system enables practical applications like mobile advertising and navigation.
- A proof-of-concept app demonstrates real-world usability in subway environments.

## Abstract

Thanks to rapid advances in technologies like GPS and Wi-Fi positioning, smartphone users are able to determine their location almost everywhere they go. This is not true, however, of people who are traveling 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 paper, 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 app that notifies users of upcoming points-of-interest and alerts them when it is time to get ready to exit the train.

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Source: https://tomesphere.com/paper/1904.01675