Complex motion pattern queries for trajectories

With the recent advancements and wide usage of location detection devices, large quantities of data are collected by GPS and cellular technologies in the form of trajectories. While most previous work on trajectory-based queries has concentrated on traditional range, nearest-neighbor and similarity queries, there is still the need to query trajectories using complex, yet more intuitive to users, motion patterns. In this paper, we describe several types of motion pattern queries for trajectories. In particular, we describe in detail two types of motion pattern queries: the flexible pattern queries, which focus on trajectories that follow a sequence of spatiotemporal events; and the density-based pattern queries, where the goal is to search trajectories that “stay together” for a long period of time. We then conclude this paper by briefly describing two other novel complex motion pattern queries that are currently under development.