Nora Parker interviewed George Percivall, the Open Geospatial Consortium’s (OGC) Executive Director for Interoperability Architecture, about the OGC’s latest Interoperability Initiative, OGC Web Services 3 (OWS-3).Percivall supervises OGC’s Interoperability Initiatives, which are the main activity within OGC’s Interoperability Program.The OWS-3 kickoff took place April 19-21, 2005 and the final demonstration of capabilities will take place October 17-20, 2005.
Nora Parker (NP): In layman's terms, what is the OGC Web Services (OWS-3) interoperability initiative? Why is it important and why should users in the geospatial industry be interested in it?
George Percivall (GP): OWS-3 is OGC's next major advance in the development of open specifications that enable geospatial interoperability.OWS-3 involves a wide scope of activities, ranging from the acquisition of geospatial data from sensors to defining a "common infrastructure" for decision support.
The Sensor Web Enablement (SWE) portion of OWS-3 focuses on making sensors accessible as enterprise Web services.The OWS-3/SWE team has been working with a variety of sensors ranging from those in a fixed location to ones located on cars, airplanes and satellites.The ground based sensors network has been designed to scale to a nationwide network.Part of this scalability is achieved by working with an IEEE (Institute of Electrical and Electronics Engineers) standard developed by the sensor hardware industry.The SWE work includes methods to request an observation to be made by a sensor on a moving or moveable platform.
The common infrastructure portion of OWS-3 involves refining the common elements of all OGC Web Services.By using a common approach for all service types, the software development for a new service is lessened. OWS-3 has continued the work from a prior testbed on workflow automation.As the variety of geospatial services continues to increase, techniques to define and automate workflows provide users with the long promised flexibility of Web services.To support all of the data sharing that is needed in this distributed environment, OWS-3 has contributed new work on Digital Rights Management for geospatial data (GeoDRM).
The decision support services portion of OWS-3 focuses on the end user or analyst who needs to pull together a variety of information to support decision making for specific circumstances.OWS-3 is defining methods to transparently convert geospatial data from other communities into terms familiar to the user.Key visualization services to support decision making include flexible methods for selecting the symbols to be displayed on a map created from various sources.
Finally, OWS-3 is beginning to define a standard for geospatially enabled video.The Web can serve video; OWS-3 has produced a "GeoVideo Service" specification for a standard way to tell you which part of the world you are viewing.
NP: What impact will OWS-3 have on the industry? What end results are expected, and what's the timing for adoption of new specifications?
GP: Like other OGC Interoperability Program Initiatives, OWS-3 has created new and revised draft specifications, implementations of those specifications and an evocative demonstration of the resulting capabilities.After the demo, the draft specifications will be presented to the OGC Specification Program, that is, the Technical Committee and the Planning Committee, for consideration to become consensus standards.This formal process by which testbeds feed into specification activity has been run very successfully by the OGC in recent years.
Some of the specifications will be updates to existing, mature, already adopted specifications, e.g., the OpenGIS Web Map Service (WMS) Specification, OpenGIS Web Feature Service (WFS) Specification, OpenGIS Web Coverage Service (WCS) Specification and OpenGIS Geography Markup Language (GML) Encoding Specification.Some of the specification work in OWS-3 will enable the Specification Program to adopt specifications that have been under consideration but that needed more work: SensorML, Sensor Observation Service, Feature Portrayal Service and several others.
The timing for adoption depends on a lot of factors and it's hard to predict, because all the members can suggest changes at any time.We will know more after the next Technical and Planning Committee meetings in Bonn, Germany, the second week in November.
New draft specifications developed in OWS-3 will begin working their way through the consensus process as discussion papers.The GeoVideo Service, for example, is a new discussion paper that is coming out of OWS-3.
NP: Who are the sponsors and what are they expecting to gain? What is the budget, and does it come solely from the sponsors?
GP: OWS-3 sponsors include: BAE Systems, IONIC Software, GeoConnections (Canada), Lockheed Martin, MAGIC Services Initiative, National Aeronautic and Space Administration (NASA), Oak Ridge National Laboratory (ORNL), NAVTEQ, Questerra, US Geological Survey (USGS) and other organizations.
Sponsors of OGC test beds generally come to the table for a couple of reasons.In the first place it ensures them that their individual needs will be addressed.Second, it gives them an opportunity to coordinate satisfaction of their needs with others by co-funding specific work. Finally, it gives them an environment to test their own work with others to confirm interoperability and give them a leg up at implementation time.
Our test bed sponsorship has been in the range of $1.5 to $2M a year, a figure that is more than matched by in-kind investment on the part of industry participants.This "in-kind" generally totals two to four times the sponsors' investment.This is what sponsors find one of the most attractive features of our Interoperability Program.