Adding Meaning to Your Steps (Keynote Paper)

Mobility data is becoming an important player in many application domains. Many techniques have been elaborated to extract statistical knowledge from the data sets gathering raw data tracks about the moving objects of interest to an application. These data tracks obey the physical-level specifications of the devices used for data acquisition (GPS, GSM, RFID, smart phones, and other sensors). Nowadays, interest has shifted from raw data tracks analysis to more application-oriented ways of analyzing more meaningful movement records suitable for the specific purposes of the application at hand. This trend has promoted the concept of semantically rich trajectories, rather than raw movement, as the core object of interest in mobility studies. This keynote paper intends to provide the foundations of a semantic approach to data about movement. It focuses on the definitions of the most important concepts about mobility data, concepts that are frequently used but rarely rigorously defined.