Addressing landmark uncertainty in VGI-based maps : approaches to improve orientation and navigation performance

Landmarks, salient spatial objects, play an important role in orientation and navigation. They provide a spatial reference frame that helps to make sense of complex environments. Landmark representations in maps support map matching and orientation, because matching landmarks to their map representations provides information about spatial directions and distances. However, effective landmark-based map matching demands sufficiently accurate georeferencing of the landmarks represented in a map, because spatial inaccuracies of landmark representations cause distortions of the spatial reference frame and derived directions and distances. The requirement of accurate landmark georeferencing imposes difficulties on the use of maps based on Volunteered Geographic Information (VGI) for map matching. Differences of the motivation, competence, and available apparatus of volunteers can cause great variations of the data quality in VGI-based maps, including spatial accuracy of landmark representations. In a series of experiments, we investigated and quantified to what extent spatial inaccuracies of landmark representations in VGI-based maps affect map matching. Based on the findings, we were able to identify critical thresholds for spatial landmark inaccuracies. Furthermore, we explored potential ways to sustain successful map matching at higher degrees of spatial landmark inaccuracies. Through visual communication of spatial uncertainties, we were able to make map users more resilient to potential inaccuracies and sustain successful map matching.