Making Time Just Another Axis in Geospatial Services

The use of large multidimensional, complex datasets to study the roots and the consequences of real-world phenomena is systematically gaining importance in the recent years. These datasets and their requisite metadata can be managed by query able databases, and the increasing processing capabilities of distributed computing and Array DBMS are opening new scenarios for Web-based access and analysis. The spatio-temporal nature of these observations requires the establishment of an automated machine-readable system that seamlessly accounts for time as not just an attribute, but rather as one more axis in the n-dimensional structure. This paper proposes a conceptual framework for the integration of temporal with spatial dimensions. Based on the widely used Geography Markup Language (GML) it exploits temporal Coordinate Reference Systems (CRSs) in analogy to, and interoperable with, well-known spatial CRSs. The proposed approach is then concretely applied to the OGC Web protocols Web Coverage Service (WCS) and Web Coverage Processing Service (WCPS), by means of which a user can visualize, aggregate, process remotely stored archives of scientific data. It is based on an open-source CRS resolver, SECORE, which translates URL identifiers of CRSs into their GML definitions. SECORE has been adopted by OGC as its standard CRS resolver, and the whole concept is supported by an ad-hoc OGC working group.