A general framework for trajectory data warehousing and visual OLAP

In this paper we present a formal framework for modelling a trajectory data warehouse (TDW), namely a data warehouse aimed at storing aggregate information on trajectories of moving objects, which also offers visual OLAP operations for data analysis. The data warehouse model includes both temporal and spatial dimensions, and it is flexible and general enough to deal with objects that are either completely free or constrained in their movements (e.g., they move along a road network). In particular, the spatial dimension and the associated concept hierarchy reflect the structure of the environment in which the objects travel. Moreover, we cope with some issues related to the efficient computation of aggregate measures, as needed for implementing roll-up operations. The TDW and its visual interface allow one to investigate the behaviour of objects inside a given area as well as the movements of objects between areas in the same neighbourhood. A user can L. Leonardi · S. Orlando · A. Raffaetà · A. Roncato · C. Silvestri (B) DAIS, Università Ca’ Foscari Venezia, Venezia, Italy e-mail: [email protected] L. Leonardi e-mail: [email protected] S. Orlando e-mail: [email protected] A. Raffaetà e-mail: [email protected] A. Roncato e-mail: [email protected] G. Andrienko · N. Andrienko IAIS, Fraunhofer Institute, Sankt Augustin, Germany G. Andrienko e-mail: [email protected] N. Andrienko e-mail: [email protected] Author's personal copy