Spatio-Temporal Reference Frames as Geographic Objects

It is often desirable to analyse trajectory data in local coordinates relative to a reference location. Similarly, temporal data also needs to be transformed to be relative to an event. Together, temporal and spatial contextualisation permits comparative analysis of similar trajectories taken across multiple reference locations. To the GIS professional, the procedures to establish a reference frame at a location and reproject the data into local coordinates are well known, albeit tedious. However, GIS tools are now often used by subject matter experts who may not have the deep knowledge of coordinate frames and projections required to use these techniques effectively. We introduce a novel method for representing spatio-temporal reference frames using ordinary geographic objects available in GIS tools. We argue that our method both reduces the number of manual steps required to reproject data to a local reference frame, in addition to reducing the number of concepts a novice user would need to learn.