Abstract
The Open GIS Consortium (OGC) has developed and released Web mapping specifications through its Interoperability Program. These specifications allow servers from multiple vendors to share and process geospatial information in an environment that is transparent to the end user. This presentation will discuss the Interoperability Program and Web mapping standards, the technology enabling interoperability, vendor participation in the program, and application of OGC conformant software to the oil and gas industry.

Opnen GIS Consortium and Interoperability

“Interoperability is the dial tone that lets systems work together transparently.”1 The dial tone analogy is apt because both people and machines understand what to do with a dial tone. The dial tone allows telecommunication devices and systems to function uniformly in complex environments because of a standard interface. The goal of OpenGIS Consortium is to build the interfaces that support a dial tone for Geospatial Information (GI) systems. Interoperable GI systems have the ability to access multiple local or remote heterogeneous systems through a single and well-known software interface.

The OpenGIS mission statement is “to deliver spatial interface specifications that openly available for global use.” Their approach to building global interoperability is outlined below:

• Organize Interoperability Projects: OGC employs a variety of innovative techniques to enable developers and integrators to rapidly and efficiently test, validate, and document specifications based on user requirements.
• Work toward consensus: OGC works by consensus to understand interface requirements and to bring developers, integrators and users into agree on specifications.
• Formalize OGC Specifications: Through OGC's structured Committee programs, OGC members develop, review, and make public OpenGIS specifications.
• Develop strategic business opportunities: OGC continuously scans the market to anticipate, identify, and engage communities in the development and adoption of OpenGIS specifications.
• Develop strategic standards partnerships: OGC maintains strong partnerships with international and commercial standards organizations and technology communities to focus the agenda for interoperability.
• Promote demand for interoperable products: Through marketing and public relations programs, OGC works with consortium members to increase awareness and acceptance of OpenGIS Specifications by users.

OGC Interoperability Program
The Interoperability Program generates Implementation Specifications, which are documented standard interfaces that software developers can use to create programs. Implementation specifications are the product of software engineering efforts in a test bed environment. Multi-participant engineering teams rapidly prototype interfaces and protocols that meet the requirements of test bed sponsors. For example, the Army Topographical Engineering Center (TEC) sponsored the first interoperable web mapping test bed.

The engineering teams use a consensus process to interpret the requirements and use industry standard software development methodologies to write software. Participants are encouraged to develop prototype implementations within their respective product frameworks, operating systems and platforms, and programming languages as long as it conforms to the specifications under development. At completion of the test bed, the participants collaboratively write and Interoperability Program Report (IPR) that documents the agreed-upon interface defined, developed, and tested in the test bed.

The IPR is submitted to the OGC body to begin the formal Specification approval process. Candidate Implementation Specification undergoes formal review, revision, and documentation. Specifications are adopted through a vote and released as a publicly available OpenGIS Implementation Specification. A draft Implementation Specification from the Interoperability Program typically uses the RFC (Request for Comment) process, used in the World Wide Web Consortium (W3C).