Spatio-Temporal Indexing Techniques

Time and space are ubiquitous aspects of reality. Temporal and spatial information appear together in many everyday activities, and many information systems of modern life should be able to handle such information. For example, information systems for traffic control, fleet management, environmental management, military applications, local and public administration, and academic institutions need to manage information with spatial characteristics that change over time, or in other words, spatiotemporal information. The need for spatio-temporal applications has been strengthened by recent developments in mobile telephony technology, mobile computing, positioning technology, and the evolution of the World Wide Web. Research and technology that aim at the development of Database Management Systems (DBMSs) that can handle spatial, temporal, and spatio-temporal information have been developed over the last few decades. The embedding of spatio-temporal capabilities in DBMSs and GISs is a hot research area that will continue to attract researchers and the informatics industry in the years to come. In spatio-temporal applications, many sorts of spatiotemporal information appear. For example, an area covered by an evolving storm, the changing population of the suburbs of a city, the changing coast lines caused by ebb and tide. However, one sort of spatio-temporal information is quite common (and in some respects easier to study) and has attracted the most research efforts: moving objects or points, for example, a moving vehicle, an aircraft, a wandering animal. One key issue for the development of an efficient spatio-temporal DBMS (STDBMS) is the use of spatiotemporal access methods at the physical level of the DBMS. The efficient storage, retrieval, and querying of spatio-temporal information demands the use of specialized indexing techniques that minimize the cost during management of such information. In this article, we report on the research efforts that have addressed the indexing of moving points and other spatio-temporal information. Moreover, we discuss the possible research trends within this area of rising importance.