Spatial Data Infrastructures
The most often quoted definition of a Spatial Data Infrastructure (Wikipedia) is that it is “a framework of spatial data, metadata, users and tools that are interactively connected in order to use spatial data in an efficient and flexible way“. Another definition is “the technology, policies, standards, human resources, and related activities necessary to acquire, process, distribute, use, maintain, and preserve spatial data” (Whitehouse Circular).
Galdos Systems defines an SDI Framework as “an event-driven peer to peer architecture which supports the real time integration of distributed spatial or spatially related databases” (see What is an SDI?). This is an approach which is more consistent with multiple interacting players, and with real time or near real time information sharing.
The INtune™ SDI Framework is a platform that provides the components to enable publication of and subscription to sensor, image, geo-spatial, and non-geo-spatial data, in a manner which is non-obtrusive and which can scale to hundreds or thousands of database or application nodes.
While based on open standards such as ebXML and GML, the SDI Framework does not require the participants to know or be aware of these standards, nor need they change existing applications or databases. The framework provides the foundation for collaborative infrastructures that can be deployed at the urban level. This ensures that data is obtained closest to the source, and that it is current, accurate, and in context.
Note further that a set of data suppliers is shown in the bottom part of the diagram, any data consumer (such as the engineering, and design systems tools shown in the top part) can also be a data supplier. The data suppliers in the bottom half are distinguished only in that there are typically government and private sector data collection activities (e.g. aerial, land survey, property management) which are not directly part of the engineering and planning process.
Conventional ideas of an SDI have been driven by national mapping agencies and have been largely focused on the resources to catalogue and provide access (portals) to small scale maps and related data sets.
Over time, geospatial data have become more distributed as different departments, organizations, and government agencies need different data models and distributed locations need to access geospatial data locally. The role of the spatial infrastructure is to enable database synchronization by enabling the user specified creation/maintenance of publication subscription relationships between the participating databases. This allows for efficient movement of data, and is relatively non-intrusive with respect to the use of existing design, engineering analysis, engineering and architectural visualization, and mapping tools.
In phases 6 and 7 of the OGC Web Services testbed, Galdos worked with an event notification architecture. An event notification architecture is a special case of an SDI application Event notification architectures are very applicable to propagating NOTAMs in the aviation domain, using domain specific terms and vocabulary.
Galdos worked with Envitia, one of Galdos’ partners, on a research project for the UK Ministry of Defence to develop a system to support the Geospatial Intelligence Integrated Reference Architecture (GI2RA). The purpose of the research is to address interoperability issues, and the harmonization of data sources into a consistent picture.
For the Institut Cartogràphic de Catalunya, Galdos built an SDI for harvesting existing data sources, and support the web portal of geospatial data.
The ArRiyadh Development Authority contracted Galdos to build an SDI for the City of Riyadh, with the objective of having a common base map that is used by all members of the group, and for which updates are shared in real-time.
Additional details on various Galdos projects are available in the Case Studies.
