Symbolic trajectories in SECONDO : pattern matching and rewriting

In this paper, we introduce a novel data model for representing symbolic trajectories along with a pattern language enabling both the matching and the rewriting of trajectories. We illustrate in particular the trajectory data type and two operations for querying symbolic trajectories inside the database system Secondo. As an important application of our theory, the classi\ufb01cation and depiction of a set of real trajectories according to several criteria is demonstrated

A Query Language for Moving Object Trajectories

Trajectory properties are spatio-temporal properties that describe the changes of spatial (topological) relationships of one moving object with respect to regions and trajectories of other moving objects. Trajectory properties can be viewed as continuous changes of an object’s location resulting in a continuous change in the topological relationship between this object and other entities of interest. In this paper we develop a query language TQ for expressing trajectory properties. Our model and query language are based on the framework of constraint query languages. We present some preliminary complexity and expressive power results for the proposed language.