Visualising Location Uncertainty to Support Navigation under Degraded GPS Signals: a Comparison Study

Degraded GPS signals can negatively affect users of mobile Pedestrian Navigation Applications. Visualization of location uncertainty has emerged as a solution to this problem that has proven beneficial to users. However, there are only a small number of different visualizations developed for this purpose. In addition, their actual impact on facilitating navigation in GPS degraded situations has not been studied well. We designed two new visualizations of location uncertainty and compared them to existing ones in terms of efficiency and user acceptance. A field-based user study(N=18) showed that the two new visualizations significantly reduced the number of wrong turns. Users preferred the landmark-based visualization most and ranked it as the most helpful visualization for judging their true location in the environment when faced with GPS degradations. Despite participants being unfamiliar with the new visualizations, the task completion time, subjective task load and user experience for them were not significantly different from the more familiar state-of-the-art visualization.