Date Added: May 2012
An increasing amount of trajectory data is being annotated with text descriptions to better capture the semantics associated with locations. The fusion of spatial locations and text descriptions in trajectories engenders a new type of top-k queries that take into account both aspects. Each trajectory in consideration consists of a sequence of geo-spatial locations associated with text descriptions. Given a user location l and a keyword set y, a top-k query returns k trajectories whose text descriptions cover the keywords y and that have the shortest match distance. To the best of the authors knowledge, previous research on querying trajectory databases has focused on trajectory data without any text description, and no existing work has studied such kind of top-k queries on trajectories.