Open Technology For A "Spatially Enabled Web" Announced

Lance McKee Vice President, Corporate Communications The Open GIS Consortium, Inc. (OGC) 35 Main Street, Suite 5 Wayland, MA 01778-5037 voice: (508) 655-5858 fax: (508) 655 2237 email:
Wednesday, 18 August 1999 UTC
Wayland, MA, USA, August 18, 1999: Maps and map queries will become a much more important part of the Web thanks to two key interoperability standards passed by members of the Open GIS Consortium (OGC) on August 13 in Southampton, England. The standards will make it much easier for businesses, citizens, and governments to find, view, pan, zoom, overlay, and query geographic image data and map data on the Worldwide Web. The new OpenGIS Grid Coverages Specification and OpenGIS Distributed Catalog Services Specification, combined with the already available OpenGIS Simple Features Specification and technology from OGC's Web Mapping Testbed, provide the means for unprecedented interoperability between systems that use geospatial data. In OGC, "Grid Coverages" refers to satellite images, digital aerial photos, digital elevation data, and other kinds of data represented in a grid cell or "raster" coordinate system. "Simple Features" refers to "vector" geodata, digital map information represented in polygons and lines. "Catalog Services" refers to a common architecture for online automated directories of geodata and geoprocessing services, rather like "spatial search engines." Cadcorp (UK), ESRI (US), Intergraph (US), Laser-Scan (UK), Oracle (US), and PCI Geomatics (Canada) made up the team that submitted the OpenGIS Grid Coverages Implementation Specification in response to an OGC Request for Technology (RFT). PCI Geomatics took the lead in this effort. A grid coverage interface provides basic image access capability for purposes of viewing a grid coverage and performing certain kinds of analysis, such as histogram calculation, image covariance and other statistical measurements. (Interoperability for a wider range of image operations awaits the OpenGIS Image Exploitation Services Specification, which is in progress in OGC's Technical Committee.) The specification supports the GeoTIFF file format, various color models, variable value sequencing and pixel ordering, and all standard grid geometries and spatial referencing systems (consistent with geometries and spatial referencing in the OpenGIS Simple Features Specification). In Southampton, Cadcorp was applauded for its demonstration of a client application panning, zooming, and querying grid coverage data on multiple vendors' servers through interfaces on the client and servers which conform to the new OpenGIS Grid Coverages Specification. Bob Moses, President of PCI Geomatics, said, "The simple maps and Earth images you've seen on the web up until now don't really show what's ahead. Geospatial technologies are so specialized and hard to integrate that they haven't been part of most peoples' information environment. Now that's going to change. We are adding 'where' to the kinds of questions the web can answer." The OpenGIS Distributed Catalog Services Implementation Specification specifies standard interfaces for online geospatial resource discovery and access services. Submitters of this specification included: Blue Angel Technologies (US), ESRI (US), Geomatics Canada (Canada Centre for Remote Sensing (CCRS)), Intergraph (US), Marconi Integrated Systems (UK), MITRE (US), Oracle (US), U.S. Federal Geographic Data Committee (FGDC), U.S. National Aeronautics and Space Administration (NASA), and U.S. National Imagery and Mapping Agency (NIMA). Other contributors included: Compusult Limited (Canada), GEODAN IT bv (Netherlands), HJW (US), Joint Research Centre - European Commission, and SICAD Geomatics (Germany). Software systems with interfaces that conform to the Catalogs specification will be able to: - Discover network-resident geospatial information resources in a distributed heterogeneous computing environment. - Create and maintain universally discoverable geospatial catalogs and catalog entries. - Create and maintain collections of universally discoverable geospatial data sets, including a metadata set and metadata entities associated with each stored data set. (The Specification does not specify metadata content. Rather, it specifies the way the metadata content is presented for discovery.) The Specification will allow use of metadata entities and elements that are a subset of the metadata currently defined in the ISO TC211 15046-15 draft document on metadata. Also, it will allow systems to associate metadata with individual data sets, a series of data sets, and individual features within a data set as currently defined in the ISO working document. - Discover the content and structure of geospatial resources available online in conformant servers. - Perform query (or selection) operations supporting discovery and access, including spatial, temporal, text, and/or numeric values, Boolean operations, spatial queries (e.g., intersect, contains, contained by, within, beyond, etc.); and deliver identity of resources (e.g., catalogs and feature collections) as a result of the query. - Retrieve complete or partial forms of geodata resources, including entire geospatial data sets or geographical subsections of data sets, returned to the requestor as a file or set of files. Products conforming to the catalog specification will simplify the lives of users of geodata and geoprocessing working in conventional application areas. But many in OGC believe the specification's greatest impact will come in the development of a much larger market for specialized geodata and geoservices, and the emergence of a "spatially aware" Internet. David Schell, President of OGC, said, "Various vendors are already offering products that conform to the OpenGIS Simple Features Specification, and we anticipate that many more will soon be productizing interfaces conforming to all three released specifications. Knowledgeable buyers are demanding interoperable products, and end users will be amazed at the variety and value of the geographic information and services these products make available." The complete OpenGIS Grid Coverages Implementation Specification and Catalog Services Implementation Specification will be released to the public on OGC's web site ( ) next year, after final editing and a brief period during which the specification will be available exclusively to Consortium members. OGC is an international, not-for profit organization working toward integration of geospatial capabilities into the world's information systems. -- end --