Indeterminacy and Spatiotemporal Data

For the majority of spatiotemporal applications, we assume that the modeled world is precise and bounded. Although this simplification is sufficient in applications like the cadastral system, it seems to be unnecessary crude for many other applications handling spatial and/or temporal extents, such as navigational applications. In this work, we explore fuzziness and uncertainty, which we subsume under the term indeterminacy, in the spatiotemporal context. To better illustrate the basic spatiotemporal concepts of change or evolution, we first show how the fundamental modeling concepts of spatial objects, attributes, relationships, time points, time periods, and events are influenced by indeterminacy, and how we can combine them. More particularly, we focus on the change of spatial objects and their geometry in time. We outline four change scenarios, which identify discrete and continuous change, and we present how to model indeterminate change. We demonstrate the applicability of this proposal by describing the uncertainty related to the movement of point objects, such as the recording of the whereabouts of buses. Finally, we describe a database schema for storing such indeterminate movement data.