Trajectory databases: Data models, uncertainty and complete query languages

Abstract

Moving objects produce trajectories. We describe a data model for trajectories and trajectory samples and an efficient way of modeling uncertainty via beads for trajectory samples. We study transformations for which important physical properties of trajectories, such as speed, are invariant. We also determine which transformations preserve beads. We give conceptually easy first-order complete query languages and computationally complete query languages for trajectory databases, which allow to talk directly about speed and beads. The queries expressible in these languages are invariant under speed- and bead-preserving transformations. © Springer-Verlag Berlin Heidelberg 2007.