Título: Dualgrid: A closed representation space for consistent spatial databases

In the past decades, much effort has been devoted to the integration of spatial information within more traditional information systems. To support such integration, spatial data representation technology has been intensively improved, from conceptual and discrete models for data representation and query languages, to indexing and visualization technologies and interoperability standards. As a result of all these efforts, Geographic Information Systems (GIS) are nowadays a widely used technology. The existing spatial databases technology provides standardized data models and operations [OGC06], based on conceptually solid spatial algebras. However, translating such conceptual models into physical models suitable for their implementation on computers, where only finite precision representations of the space can be used, becomes a difficult task. As a result, the current implementations of physical models are generally severely limited when compared to their conceptual counterparts. They attempt to provide an implementation fulfilling the original conceptual algebras, but at the physical level they cannot further ignore the problem