Geo-position technologies in city use research: accuracy evaluation in the context of university students mobility

Resum

In the last years the broad potentiality and utility that geo tracking systems can offer have been explored in research fields not only related to geography, but medicine, leisure and tourism as well. Although this technology has been employed in mobility and transportation system analysis, there is still a lack of studies in the urbanism field. This research seeks to evaluate the accuracy of geo-positioning technology tools in the analysis of peoples’ movement and flows in the city. Therefore, we have performed an experiment using Campus Mobility, an open source application for Android smartphones developed by the Mobility, Transport and Territory Studies Group (GEMOTT) of the Autonomous University of Barcelona (UAB) based on SpaceMapper by John Palmer. While activated, the app tracks and records automatically spatiotemporal data from volunteers’ smartphones every two minutes through the GPS. By the end of the experiment, a large dataset with more than 47.000 entries has been generated, including geographical position (latitude and longitude), date and time (timestamp) as well as an anonymous user ID. Additionally to the experiment, a survey has been applied to volunteers in order to contrast and complement results from automatically gathered data and users answers. From the obtained dataset, we have investigated users’ paths, movement and meeting points analytically and graphically, aiming to recognize patterns in volunteers’ displacement and to detect possible anomalous data. For the graphic analyses we have created data visualizations in addition to dynamic maps that have been developed using ArcGIS and CartoDB tools. Both outcomes were combined in order to gain a deep understanding on the shortcomings and possibilities that geo-positioning technology tools offer to urban investigation field. Finally we conclude that, despite minor errors, geo-position technology tools provide new great possibilities for city flows and mobility studies, being able to gather automatically a very large amount of detailed data that would be impossible to collect without an automated process. GPS tracking can be considered a powerful resource for urban studies, although those tools are not entirely accurate if applied to a very small scale analysis.