Speaking at a conference hosted by Ordance Survey, Sir Tim Berners-Lee explains how Semantic Web technology can advance GIS information sharing and interoperability. The detail of his speech is covered in this ZDNet article.
Few items mentioned in the article worth our attention.
In geospatial information systems (GIS), data integration is often a problem. Different systems may use different vocabularies to represent the same abstract concept, and different systems may express data values in different unit of measure (UOM). This problem may be of interest to the Semantic Web community because it’s a different kind of semantic interoperability problem.
After reading this blog entry, a reader asks the following:
The definition [of geospatial semantics] is convincing. However, could you tell the difference between the “Geospatial semantics” and Egenhofer and Mark (1995)s’ “Naive Geography” which defines as : “The body of knowledge that people have about the surrounding geographic world.”
In this post, I will try to answer Andrea’s question.
I believe there are similarities and differences between the studies of Naive Geography and Geospatial Semantics.
OGC (Open Geospatial Consortium) published two online multimedia demonstrations documenting the milestones achieved in the OGC Web Services Phase 3 Initiative, (OWS-3). The goal of OWS initiatives is to promote and demonstrate the use of various OGC open geospatial specifications.
In OWS-3, participants worked in the following areas:
I watched the video, and I think it’s well made. The demo also gives a good overview of what OGC does and the importance of data interoperability.
An official announcement from OGC is available online.
Jeff Thurston at Vector One writes,
“I think interoperability is not THE issue. The issue in the GIS and geospatial arena is structural barriers internal to enterprises. It is all about breaking the barriers between people.
We need to get back to the basics, discussing what it is we want to do with the many high quality tools we have created across this industry and how they can really be used - and - changing the structural processes in organizations to make it happen.”
I think interoperability is a problem, at least from the knowledge integration point of view. Organizations have invested a lot of time and money to collect information. Different information collected over the years often is not stored in the same representation format.
Though his suggestion makes great sense, I doubt that it’s the most cost-effective solution. It’s not always economical to reconsolidate datastores just because we want different schemas to align and use shared vocabularies. NGA people told me once, “reconsolidation is expensive”.
I believe semantic interoperability is a better solution.
The most value asset in a GIS system is data. Without data, a GIS system is like a computer system with the best peripherals but only with an empty hard drive — it’s useless. If data is so important, it is necessary for us to understand the role of data in the future GIS systems — i.e., the Geospatial Semantic Web.
The ESRI Federal User Conference (FedUC) is January 31–February 2, 2006, at the Washington Convention Center in Washington, D.C. The conference supports those who deploy ESRI software for geoprocessing and analysis, integrated work flows, and intelligent collaboration across government. (source blog)
Going through the program schedule (pdf), I see a lot of interesting application domain that could exploit Semantic Web technology. I think the use of ontologies and RDF can be useful in the following domains:
I’m quite disappointed to see the word “semantic” is not mentioned anywhere in the entire 27 pages document. The word “intergration” is mentioned is 15 times. Do people really believe that knowledge integration problems can be solved without some kind of understanding of the semantics?