Moving balloon algebra: Design, implementation, and database integration of a spatiotemporal data model for historical and predictive moving objects

Spatiotemporal databases deal with geometries changing over time. Recently, moving objects like moving points and moving regions have been the focus of research. They represent time-dependent geometries that continuously change their location and/or extent and are interesting for many disciplines including the geosciences, geographical information science, moving objects databases, location-based services, robotics, and mobile computing. So far, a few moving object data models and query languages have been proposed. Each of them supports either exclusively historical movements relating to the past or exclusively predicted movements relating to the future. Thus, the query support for each model is limited by the type of supported movements. This presents a problem in modeling the dynamic nature of a moving object when both its known historical movement and its predicted future movement are desired to be simultaneously managed and made available for spatiotemporal operations and queries. Furthermore, current definitions of moving objects are too general and rather vague. It is unclear how a moving object is allowed to move or evolve through space and time. That is, the properties of movement (like its continuity) have not been precisely specified. It is also unclear how, in a database context, future predictions of a moving object can be modeled taking into account the inherent uncertainty of future evolution. Moreover, implementations of spatiotemporal data types and operations are rare and their integration into extensible database management systems has been so far nonexistent. In this research, we present a new type system and query language called Moving Balloon Algebra consisting of a moving object model that is able to represent the dynamic nature of moving objects while providing integrated and seamless support for both historical and predicted movements of moving objects. The goal is to go beyond existing moving object models by collectively integrating existing functionalities as well as introducing new ones. From a conceptual standpoint, this algebra provides a formal definition of novel spatiotemporal data types, operations, and predicates as well as introduces new types of spatiotemporal queries. Beside these conceptual contributions, an implementation of the algebra is provided in the form of a database-independent type system library, and its integration into a relational database management system is demonstrated.