T he World Wide Web Consortium
(W3C) defines a web service as “a software system designed to support interoperable machine to machine interaction over a network.” Web services are thus the foundation for web-based distributed computing.

“Interoperable” is the key word. A web service is often an open API (application programming interface) that a client uses in a request to invoke a processing operation on a remote system that hosts the requested services. The “GeoWeb” is increasingly a network of interoperable resources available through open interface and encoding standards developed collaboratively by users and vendors in a formal international consensus process in the Open Geospatial Consortium, Inc. (OGC®).

OGC’s members have aligned their thirteen-year-old collaborative effort with other consensus standards efforts that have produced related standards for web services. As a result, online geoprocessing systems functioning as “servers” can respond to web-delivered commands from diverse “client” software processes to provide geoprocessing web services. These services can interactively retrieve, display or operate on a user-specified “bounding box” of data, which wasn’t possible before, except in vendor-limited environments. But standards-based services enable much more, such as:

• Real-time conversion of map symbols to suit the user's needs
• Robust access to sensor networks as spatial data
• Access to sophisticated GIS processing functions using only a web browser
• An open framework for location based services
• Encoding of geospatial data in XML (eXtensible Markup Language), which opens many other possibilities

Other standards enabled capabilities are under development and will emerge in adopted standards and commercial implementations in the coming months and years.

In this article we look at how Web services are beginning to play a role in three areas: enterprise architecture, AEC/CAD/Geospatial/3D applications and data quality and preservation efforts.
Geospatial web services in enterprise architectures

A number of key geospatial web services standards have been adopted in recent years by the members of the Open Geospatial Consortium, Inc. (OGC) and ISO TC 211, and many commercial products [http://www.opengeospatial.org/resource] now implement these standards. This market acceptance has logically led to standards based geospatial web services being written into the information system plans of governments and businesses. These plans are formally documented as actionable “enterprise architectures”.

Creating an enterprise architecture involves first carefully documenting the current and desired relationships among business and management processes, looking closely at information requirements and information flows. In subsequent steps, enterprise architects specify the “nuts and bolts” of information and communication technology (ICT) systems and best practices that support the business and management processes.