FAQs - OGC's Global Organization

Q and A: 
  1. Is OGC an International Organization?
  2. What is the European Special Interest Group (Europe SIG)?
  3. What is OGC Europe?

Q: Is OGC an International Organization?

A: Yes. OGC's members and directors are from many countries. OGC began in the US, but as of August 30, 2003, 256 industry, academic, and government organizations from 31 countries are members of OGC, and a majority (146) of those are not US organizations. Among the current members, there are 18 sub-national (state, provincial and local) agencies, 29 national agencies and three international agencies, including the United Nations. OGC works to recruit members from around the world and encourages them to take advantage of the opportunity to lead in the development and use of OpenGIS Specifications. It is an international standards organization in the same way that the World Wide Web Consortium (W3C) and the Internet Engineering Task Force (IETF) are international standards organizations.

Non-US organizations in OGC report that the process is democratic, and they believe results will benefit all countries. Commercial providers of technology as well as users in all countries can benefit more from participating in the process than ignoring it.

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Q: What is the European Special Interest Group (Europe SIG)?

A: OGC has about 91 members with headquarters in Europe and at least 30 "multi-national" members who are active in Europe, working from European addresses as European corporations. This group of organizations comprises the domain of membership for OGC's Europe Special Interest group (Europe SIG). The Europe SIG was organized by the Planning Committee, "to define organizational and business approaches relating to European member issues that have significance for the development and implementation of a community-wide OpenGIS architecture, and to stimulate the further growth of the European geographic information (GI) market." The charter further charges the Europe SIG "...to assess issues of the European members of OGC which relate to the requirements, development and general acceptance of the OpenGIS Specification, and to recommend organizational approaches within OGC to ensure these issues are appropriately assimilated within the specification process." In other words, the Europe SIG was established to grow a program of activity which will strengthen the OpenGIS process in Europe and make it more valuable to Europeans.

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Q: What is OGC Europe?

A: Open Geospatial Consortium (Europe) Limited (OGCE) is a  not for profit subsidiary of OGC whose purpose is to conduct business in Europe and Australia on behalf of OGC's mission, goals, and objectives. This company promotes the development and use of OpenGIS standards and represents the OGC's European-based membership in regional fora, meetings and initiatives. OGCE provides consultation on architecture, proof of concept projects, procurement readiness, and program support.

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Frequently Asked Questions (FAQs): 

FAQs - The Role of OGC

Q and A: 
  1. Where is geoprocessing technology headed?
  2. What is the difference between "business GIS" and "the spatially enabled enterprise?"
  3. How will OGC Web Services (OWS) change the World Wide Web?
  4. What role does OGC play in the development of Location Based Services (LBS)?
  5. How does OGC facilitate e-commerce in geodata and geoprocessing services?
  6. What is Sensor Web Enablement?
  7. What are Geospatial Fusion Services (GFS)?

Q: Where is geoprocessing technology headed?

A: Geographic information will no longer be segregated in GIS and earth imaging systems. It will be easily discovered, accessed, integrated and used. The level of expertise required to use geospatial data will be greatly reduced because the data types, data formats, resolutions, coordinate transformations, and semantic issues will usually be handled automatically and invisibly. The questions and answers below provide more detail.

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Q: What is the difference between "business GIS" and "the spatially enabled enterprise?"

A: "Business GIS" is a term that evolved to describe business applications of geographic information systems. Most such applications involved sales and marketing analysis on standalone software systems that were "islands of automation" in the enterprise. With the advent of OGC's open geoprocessing standards, businesses are finally able to go far beyond business GIS, bringing the power of spatial analysis and spatial awareness to any department. Everything and everybody is somewhere and everything happens somewhere, so it is logical that many workflows can be assisted by information systems that fluidly publish, discover, display, and process spatial information. Mobile, location aware devices, Web Services and spatial extensions to general purpose databases further support "spatial enablement" of the enterprise.

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Q: How will OGC Web Services (OWS) change the World Wide Web?

A: Now that vendors of Web-based software are implementing interfaces conforming to OpenGIS Specifications, geoprocessing software of different kinds from different vendors is beginning to work together "one-to-many" on the Web. When OpenGIS Specification conformant interfaces have been adopted on a large scale (and this is happening) any client will communicate with any server as if they were in the same vendor family of products. So the Web will be full of maps and spatial services, just as it is now full of text and simple images, and all of this will be available to everyone (unless restricted by the owner). Catalogs conforming to the OpenGIS Catalog Services Specification will enable "spatial search engines" for discovery of both online geoprocessing services and online geodata sources. Geospatial portals based on OpenGIS Specifications will serve as hubs for users and providers of geospatial information to share data much more easily than before. This describes the "Spatial Web."

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Q: What role does OGC play in the development of Location Based Services (LBS)?

A: In OGC's OpenLS activities, OGC members have cooperatively developed the “GeoMobility Server” (GMS), a set of specifications for open interfaces and schemas that support Location Based Services. These standards are necessary if there is to be communication of location (and time), route, types of service, etc. across diverse technology platforms, application domains, classes of products, carrier networks and national regions.

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Q: How does OGC facilitate e-commerce in geodata and geoprocessing services?

A: OGC members have cooperatively developed a standards framework for 1) easy Web-based geodata discovery and access and 2) geoprocessing Web Service discovery and access. This framework is consistent with the larger IT industry's evolving framework for e-commerce, which includes facilities for security, authentication, authorization and monetary transactions. The detailed requirements of e-commerce that are unique to geodata and geoprocessing services, and a proposed set of interfaces to meet these requirements, have been documented in an OGC discussion paper titled, "Web Pricing & Ordering Service."

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Q: What is Sensor Web Enablement?

A: OGC members have developed a set of specifications to support the building of "sensor webs," that is, networks of Web-connected geo-located sensors and imaging devices of all kinds. The specifications provide standard XML encodings for data describing sensors and sensor data and they specify interfaces for querying and controlling the sensors and imaging devices. The Observations & Measurements specification, which provides general models and XML encodings for sensor observations and measurements, promises to become an indispensable standard in science and engineering.

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Q: What are Geospatial Fusion Services (GFS)?

A: OGC members have developed a set of specifications to support the merging of diverse kinds of information that may usefully be organized as spatial information, even though they are not usually referenced spatially. For example, photographs, video clips, audio recordings and text documents referring to a place can be georeferenced and treated as spatial data, and they can be indexed for retrieval by queries that use earth coordinates or bounded regions.

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Frequently Asked Questions (FAQs): 

FAQs - OGC and "Openness"

Q and A: 
  1. What is OpenGIS®?
  2. What is an "open standard"?
  3. Does OGC develop open data formats? What is GML?
  4. Why are there different membership levels in OGC?
  5. What are "open portals?"
  6. What are "open procurements?"
  7. What can users and buyers of GIS and other geoprocessing software do to get more "openness"?
  8. Does OGC promote standard data models and standard metadata schemas?
  9. How do OpenGIS Specifications support system integration?
  10. What is Interoperability?
  11. What are "open systems" and "open interfaces?"
  12. What is an "open platform?"
  13. Why are architectures important?
  14. What is an application schema?

Q: What is OpenGIS®?

A: OpenGIS is an adjective describing specifications and other products of OGC's consensus process that support transparent access to heterogeneous geodata and geoprocessing resources in a networked environment. The goal of OGC is to provide a comprehensive suite of open interface specifications that enable developers to write interoperating components that provide these capabilities.

OGC registered the trademark "Open GIS" and OpenGIS® in countries around the world to assert the importance of open standards in geoprocessing and to protect its standards with a legal brand. A software vendor whose software implements interfaces based on OGC’s standards can claim that a product "implements" particular OpenGIS Specifications. If the product has passed a conformance test for a particular OpenGIS Specification, the vendor can claim that its product conforms to that version of a specification and it can use OGC’s trademarks to assure buyers of the veracity of those claims. The phrase "open GIS" (with a small "o") is also a trademark of OGC, with the same meaning as "Open GIS," though "open GIS" is not a registered trademark.

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Q: What is an "open standard"?

A: OGC defines an open standard as one that:

  1. Is created in an open, international, participatory industry process, as described above. The standard is thus non-proprietary, that is, owned in common. It will continue to be revised in that open process, in which any company, agency or organization can participate.
  2. Has free rights of distribution: An "open" license shall not restrict any party from selling or giving away the specification as part of a software distribution. The "open" license shall not require a royalty or other fee.
  3. Has open specification access: An "open" environment must include free, public, and open access to all interface specifications. Developers are allowed to distribute the specifications.
  4. Does not discriminate against persons or groups: "Open" specification licenses must not discriminate against any person or group of persons.
  5. Ensures that the specification and the license must be technology neutral: No provision of the license may be predicated on any individual technology or style of interface.

    By this definition, a de facto standard established by one company or an exclusive group of companies or by a government is not an open standard, even if it is published and available for use by anyone at no charge. The Web, and the Spatial Web, cannot depend on proprietary standards.

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Q: Does OGC develop open data formats? What is GML?

A: In the not so distant past, it was important to know whether your data was in a particular vendor’s (published or unpublished) format, such as SHAPE or DXF or in an open government format such as TIGER or VPF, or in an exchange format such as SDTS or SAIF. Now, format is not a major issue when vendors’ systems communicate through open interfaces. People sometimes want to archive whole data sets in the format native to the software they are using, or in an exchange format, but bulk conversion of data files from one format to another is becoming less and less necessary. The new world of ‘open’ enables conversion "on the fly" when the data are needed, "invisibly" to the user. This not only avoids the enormous investment in converting data that may never be used afterwards, but it makes it easy to provide or find up-to-date data as well.

Ironically, the Web provides justification for something like a universal open format: Virtually all Web browsers now include software to process text encoded in the eXtensible Mark-up Language (XML). XML can be described as a language for creating self-describing data files, that is, data files whose headers explain how to interpret the data that comes after the header. This has turned out to be a very powerful concept. Scores of industries and professional domains have seized on the opportunity to develop XML schemas (essentially formats) to capture the specific kinds of information that need to be shared within those industries and domains by organizations whose legacy systems are very different from each other’s.

Similarly, the members of OGC developed the Geography Markup Language, which is well on its way to becoming the standard XML encoding for geospatial information. It happens that XML-encoded geospatial metadata, (parts of which conform with GML) are a keystone element of the OGC Web Services architecture that makes possible detailed, complex, automated searches for spatial data and spatial services on the Web. Also, GML separates content from presentation, so the way in which data is presented (on desktop systems and PDAs, for example) is entirely under program control and can thus be tailored automatically to suit display device capabilities or application requirements. Very importantly, one of the major breakthroughs with GML is that, when used with XML tools, GML makes it possible to resolve many of the difficulties associated with incompatible data models.

It is not difficult to create profiles (application-specific variations) of GML, and this is what most data developers will do. The Ordnance Survey of Great Britain and the US Census Bureau (in its TIGER data) have committed to GML. But everyone in the geoprocessing industry should be aware that it is also easy to create new XML schemas for geographic information that are not profiles of GML, and herein lies the risk of a new obstacle to interoperability.

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Q: Why are there different membership levels in OGC?

A: OGC is a membership organization supported solely by membership fees and fees paid by sponsors of Interoperability Initiatives. Membership levels are designed to accommodate different organizations' range of commitment, ability to pay, benefits of membership and reasons for joining. These considerations are balanced against the longstanding policy to make membership affordable for every organization that wants to be involved and the need to pay staff and consultants to organize meetings, promote the consortium and its activities, and maintain the Web site and specification documents.

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Q: What are "open portals?"

A: Geospatial portals can be thought of as the "hubs" or "geoinformation resource supermarkets" in the Spatial Web. A portal is a Web site that gives visitors organized access, typically through catalog services (services not too different from those provided by search engines), to data and processing resources on the Web, and perhaps also to people, organizations and publications. A portal offers an organized collection of links to many other sites. A portal thus can be used to aggregate content. And by attracting a large number of visitors who share a common interest, a portal also aggregates content seekers for the benefit of content providers and potentially for the benefit of that community of content seekers.

Users of geospatial portals based on the OpenGIS Portal Reference Architecture are able to immediately access – pan, zoom, compose, save and print – views of digital geospatial content held on diverse Web-connected servers. Multiple maps from multiple servers can be overlaid and "flipped through." Data providers register their data for access via the portal. Applications (and other portals) can integrate portal resources into information offerings and work flows.

The OpenGIS Portal Reference Architecture is a comprehensive, flexible, vendor-neutral framework for implementing geospatial portals, a design that is based on a collection of OpenGIS Specifications for software interfaces and GML encodings. It details the kinds of requirements that need to be considered in various spatial portal application scenarios and shows how to meet those requirements with components whose interfaces implement OpenGIS Specifications.

Software comprising a portal can be from one or several vendors. The key criteria for an open portal is that it be fully interoperable with all the other spatial resources on the Web that are equipped with interfaces, encodings etc. that implement OpenGIS Specifications.

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Q: What are "open procurements?"

A: Open interfaces make it possible to specify in a procurement a type of software component, rather than specifying one particular vendor’s software. The goal is to be able to build incrementally with "best of breed" components, and to be able to "swap out" and "swap in" software components. For example, the procurement language might be, "Application shall implement a geocoding service that is accessible via the OpenGIS Location Service Geocoder Interface Specification." This offers geoprocessing software buyers unprecedented savings and flexibility. With respect to a geospatial portal or other Web-based geospatial solution, whether or not the solution uses components from multiple vendors, all of its connections to outside resources and users must be through open interfaces. If not, the implementation remains a closed system, a stovepipe, an island of automation that prevents present and future inter-institutional interoperability.

Open standards make open procurements possible. The open procurement specifies functional requirements and interoperability requirements. Products can easily be benchmarked in an interoperability pilot. Vendors that meet contractual requirements and demonstrate functional requirements and interoperability are qualified to provide components. This multi-vendor procurement process has been used successfully by numerous government organizations over the years.

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Q: What can users and buyers of GIS and other geoprocessing software do to get more "openness"?

A: Standards setting ultimately depends on users buying products that are based on standards. Vendors in OGC who have committed significant resources to developing the OpenGIS Specifications, with input from users, do so as an act of faith. They have implemented many of these specifications in products, but they depend on their customers and potential customers to understand the standards and ask for them. Public and private sector organizations owe it to themselves, their customers, shareholders, stakeholders, data sharing partners and constituencies to use the OpenGIS Reference Architecture (ORM) and the OpenGIS Portal Reference Architecture as models for their next purchases. These reference architectures make it easy to discern which OpenGIS Specifications are relevant to their needs. At a minimum, they need their local governments to ask for OpenGIS Geography Markup Language (GML), Web Map Server (WMS) and Web Feature Server (WFS) Specifications in software procurements.

Vendors and consultants must encourage their customers to make their data available in GML. (This doesn't mean users need to change their data models. They just need to convert their data to GML so it can be "understood" by XML-parsing software.)

User organizations in OGC that have committed resources to developing the OpenGIS Specifications by providing requirements in testbeds and pilot projects need other user organizations to help "move the ball forward." Particularly with respect to governments’ needs to protect critical infrastructure and citizens in time of disaster, widespread user acceptance of open standards is critical. Similarly, industries that depend heavily on geospatial information are motivated to reduce their costs of system integration and data integration, and they can do this best if all their internal geoprocessing systems and the geoprocessing systems of data sharing partners are interoperable. In areas like location-based services and sensor webs, the opening of whole new markets depends on product strategies based on open standards.

So, it is incumbent upon buyers of geoprocessing software, data and services to carefully review their requirements and draft interoperability architecture documents that lead to purchase of solutions that implement the appropriate OpenGIS Specifications. This can be done piecemeal, one upgrade or add-on at a time, or, if it is time for the organization to put a whole new solution in place, it can be done comprehensively, all at once. OGC and OGC's members can help by examining use cases and explaining where open interfaces can be specified into the architecture on which procurements will be based.

Much is at stake, and much will be set in motion when a large number of people each take a small step in the direction of openness.

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Q: Does OGC promote standard data models and standard metadata schemas?

A: OGC encourages these efforts, recognizes their value and their limitations, and provides a framework of software interface standards and data encoding standards that helps people make the best possible use of others' data despite dissimilar data models and metadata schemas.

A data model details how to take real world objects or phenomena and make them useful in computer applications. In the geospatial world the focus is on points, lines, polygons and attributes of geographic features.

Metadata is "data about data," important in finding data and evaluating its usefulness for a particular purpose. A metadata schema is a template or structure for metadata.

Without coordination, different people and organizations working at different times on different kinds of projects produce data using different data models, and they describe their data using different metadata schemas. The differences have made it very hard to share and combine data. Coordination efforts are underway in many countries to develop and adhere to standard data models and standard metadata schemas. However, a nationwide standard that meets both local and national needs is very difficult to achieve, and the cost of attaining consistent data content seems to many (particularly those at the local level) to make this an unreachable goal.

It happens that standard data models and standard metadata schemas can be very useful even if no one follows them precisely. The standards will have an important role as "Rosetta stones" that enable users to "imperfectly" map data in a "local" data model to a common model, thus making their data "as useful as possible" to others. One-to-one mapping of data models is unworkable when there are thousands of models to map between. GML enables a one-to-many solution.

One-to-many mapping of data models is made possible by XML tools. The XML tools (prototyped in OGC's GOS-TP and CIPI-2 pilot projects) map GML-encoded data from a local model to the national model and vice versa. The data thus becomes "as useful as possible" to the data sharing partner who uses a different model. Certain elements of one model do not map to the other, but the XML tools make these inconsistencies plain in all their details, so that it is easy for data managers to focus on the critical schema elements that don’t map. This makes both data sharing and data coordination much easier. It makes it easier for people at the local level to accommodate national standards in an affordable and practical way, and it makes it easier for people at the national level to work with local data that hasn’t been converted in all its details to the national standard.

Another benefit of the GML approach is that this technology makes content standards easier for software vendors and integrators to support. Currently, content standards are expensive to support, and smaller companies that do not support them are at a disadvantage. The new approach thus enhances competition, increasing the choices available to users in the market.

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Q: How do OpenGIS Specifications support system integration?

A: Integration in our industry means making spatial data accessible from multiple technologies and software vendors and making spatial data and spatial functionality available to other IT systems such as customer response management, logistics, location-based services for wireless devices, etc. The benefit is that users can thus access, combine, and disseminate geospatial information from distributed and varied information sources. Integration streamlines workflow and reduces costs of information production, maintenance and dissemination.

Integration is far more efficient, with significant immediate and downstream cost savings, if the integration can be accomplished with open standard interfaces instead of proprietary and/or custom interfaces. Enterprise systems integrated using open interfaces can enjoy the "network effects" that result from the same interfaces being used in the world outside the enterprise. An open interoperability platform motivates vendors to introduce more tools, components, and niche solutions for integrators to employ. OGC’s goal is to create a single, vendor-neutral infrastructure for integration that works everywhere, across all platforms, technologies and types of devices.

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Q: What is Interoperability?

A: Software interoperability describes the ability of locally managed dissimilar systems to exchange data and instructions in real time to provide services (computing services as in "client/server" or "Web Services"). Interoperable systems are generally distributed (i.e., at different places on the network), though in OGC’s case, interoperability also applies to different types of systems or similar systems from different vendors communicating while running on the same computer. The interoperability challenge, successfully met by means of consensus reached in inclusive consensus processes, is to balance the users' need for compatibility with the autonomy and heterogeneity of the interoperating systems.

It is important to remember that proprietary algorithms typically run unseen in the "black box" component whose public face is the open interface. Some server components will outperform others and/or offer capabilities not offered by others, though they may all communicate with clients through a common interface. In an interoperable environment, competition among vendors is based on such differences in capabilities and performance, and is not based on which format the user’s data is stored in, or which software provides the display function.

Interoperability also refers to interoperability across time (evolution of systems over time with backward and forward compatibility). When users participate in standard setting, backward and forward compatibility have a high priority.

Recall that the Internet Protocols (IP) were introduced as inter-net protocols, for inter-networking, that is, moving data between different networks. At the time there were many different networks, whose names we no longer remember. Inter-networking gave way to the use ONLY of the IP protocols. The result was the Internet and then the World Wide Web, which provided a platform, an interoperability platform, supporting an extraordinary proliferation of services and applications. This is the appropriate model for a geoprocessing interoperability platform.

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Q: What are "open systems" and "open interfaces?"

A: The definition of open systems has changed over time, but today open systems are usually considered to be systems that interoperate through open interfaces. An interface is simply a common boundary, a means to make a connection between two software components. An interface on the client presents an ordered set of parameters (with specific names and data types) and instructions (with specific names and functions) to an interface on the server that is structured to read and respond to just such a set of parameters and instructions. Thus an interface enables one processing component to exchange data and instructions with another processing component.

Some interfaces satisfy part but not all of the "openness" definition above. The information technology world has been steadily evolving toward greater openness, so many older systems still in use interoperate in what now appear to be limited ways. Such systems from a variety of geoprocessing software companies use interfaces that the companies have published for coding by integrators and application developers. Reaching that situation was progress, considering that at one time, few proprietary interfaces were published. From today’s perspective, however, there are reasons not to depend on such published, but proprietary interfaces.

- In the old paradigm, a client system needs a separate interface for each vendor’s system. The biggest advantage of open interfaces is "build one, access many." With truly open systems, solution providers no longer need to build custom interfaces. Users are no longer isolated in technology stovepipes and no longer captive to ("locked in to") single vendor solutions. "Stovepipe" is a metaphor commonly used to describe systems that are integrated "from top to bottom" but isolated laterally, i.e., from other systems. A stovepipe system might be a system from a single vendor or it might be a system built by an integrator, but it is not an open system.

-- From time to time, vendors change or enhance their interfaces, forcing client systems to change and forcing users to upgrade, perhaps without notice or opportunity for input. In contrast, the consensus process in a consortium like OGC gives integrators and application developers both notice and opportunity for input, increasing the level of continuity in new releases. Open standards impose a few constraints on developers, but they open huge opportunities, as demonstrated by the explosion of innovation and business opportunity that has resulted from the Web.

-- Integrators and application developers will probably spend more time learning how to use the proprietary interfaces than they will spend learning how to use OGC’s interfaces. One bad result of the old paradigm has been that integrators tended to learn and then use one system exclusively simply because the cost of mastering more than one is too high, which further limits the choices available to the user. One reason open systems result in greater innovation is that they remove this burden from development budgets, freeing resources for innovation.

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Q: What is an "open platform?"

A: The meaning of open platform depends on the context. In general, the term platform used to denote any specific hardware and operating system combination, such as the Windows/Intel platform or the Solaris/SPARC platform. It is now used more generally to describe an application programming interface (API) or set of APIs that provide access to computing power, database, GIS or other services hidden "underneath" those APIs. The acronym "API" is giving way to "interface" in programmer-speak. By the definition of "open" in this paper, no single vendor provides an open platform unless all the exposed interfaces are open interfaces. An open platform needs to be like the IT industry’s Web Services platform, which is still, as of August, 2003, largely unencumbered by proprietary restrictions and is the product of a consensus process.

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Q: Why are architectures important?

A: Today's enterprise information systems depend on interfaces that enable disparate parts of the systems to work together. An architecture provides an overall plan that shows what parts are needed, based on current and projected workflows, and what interfaces and data models are needed. Architectures can be based on proprietary or open interfaces. Architectures based on OGC's OpenGIS Reference Model use open interfaces based on OpenGIS Specifications. Such open architectures enable the integration of components from any vendor that implements the open interfaces, and they provide for direct (no integration required) interoperability with other systems architected using the same open interfaces.

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Q: What is an application schema?

A: An application schema is an information model for a specific information community. An application schema is set of conceptual schema for data required by one or more applications. An application schema contains selected parts of the base schemas presented in the ORM Information Viewpoint. Designers of application schemas may extend or restrict the types defined in the base schemas to define appropriate types for an application domain.

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Frequently Asked Questions (FAQs): 

FAQs - OGC Abstract Spec

Q and A: 
  1. What is the "Abstract Specification" and what are "implementation specifications"?
  2. What's the difference between a specification and a standard?
  3. What is the "OGC Technical Baseline"?
  4. What is the OpenGIS Reference Model (ORM)?
  5. What OpenGIS Implementation Specifications have been completed?
  6. What OpenGIS Specifications remain to be developed?
  7. What are OGC Web Services (OWS)?
  8. What other distributed computing platforms does OGC work on besides the Web?

A: The OpenGIS Abstract Specification formally documents, at a "high level," the terms, definitions and information models, such as geometry, along with software behaviors, on which members have reached consensus. Thus, the Abstract Specification provides the lingua franca and foundation upon which OpenGIS Implementation Specification are based. OpenGIS implementation specifications are actual engineering specifications that software developers can implement in applications and products. (For an example of the Abstract Specification, see Topic 2: Spatial Reference Systems. For an example of an implementation specification, see OpenGIS® Web Map Service Implementation Specification.)

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A: A standard is a specification, but a specification is not necessarily a standard. In the context of geoprocessing, specifications (whether they are standards or not) are documents that describe protocols (e.g., TCP/IP), data encodings (e.g., GML), software interfaces, and other aspects of information and process sharing. They provide guidance to the software developer regarding software design and behavior. A standard is a specification that developers in numerous companies can use to ensure that their products "work together." (In the context of geodata, specifications can describe content (e.g. ISO 19115 Metadata Content Standard), formats (e.g. JPEG, PNG), schemas, quality, etc.)

The authority of a specification rests on its inherent technical excellence. On the other hand, the authority of a standard derives from the breadth of its acceptance in the marketplace and the authority of the standard setting organization sponsoring it. The standard setting organization may be an industry standards consortium such as OGC, W3C or IETF or it may be an official standards organization such as the International Organization for Standardization (ISO) or ANSII. Both types of organizations develop specifications that are intended to be standards.

Every software company develops specifications to guide development of their proprietary technologies. Sometimes these are later released to the public, usually to strengthen the competitive market position of the vendor. Such proprietary specifications may become "de facto" standards.

OpenGIS® Specifications, on the other hand, are "consensus standards" similar to HTML, XML, TCP/IP and the other standards that define the Internet and the Web. OpenGIS Specifications are conceived, written, and approved through a member consensus process. This process includes active participation and review by users, integrators and vendors. Thus OpenGIS Specifications are technically of very high quality, they are specific enough to ensure interoperability, and they are standards by virtue of the market acceptance that results from the participation in OGC of so many of the industry's key technology providers and users. Several OpenGIS Specifications have also been adopted by ISO as International Standards and more are in ISO's review process.

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A: The OGC Technical Baseline is the set of all Adopted Specifications plus all other technical documents that have been approved by the OGC Technical and Planning Committees, including the OpenGIS Reference Model, OpenGIS Abstract Specifications, Recommendation Papers, and Discussion Papers.

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A: The ORM is a document, part of the OGC Technical Baseline, that provides an overall conceptual framework for building geospatial processing into distributed systems in an incremental and interoperable manner. The ORM serves as a guide to designing enterprise architectures whose data models and open interfaces support the near-term and long-term vendor-neutral integration of spatial capabilities.

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A: Click on "Documents =>OpenGIS Specifications" on OGC's web page or go directly to them to see the current list of adopted OpenGIS Implementation Specifications.

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A: Many OpenGIS Specifications are in process and others are sure to be proposed. You can learn about many of those that are in process by reviewing the Requests For Comment, Recommendation Papers, and Discussion Papers that can be accessed through the OGC Web site home page.

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A: OWS refers to all OpenGIS Specifications for interfaces, encodings, etc. that apply to Web-based geoprocessing. (Some OpenGIS Specifications apply in the case of two dissimilar systems communicating while running on the same computer or while using a distributed computing platform other than the Web.)

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A: OGC members have developed OpenGIS Specifications for CORBA and SQL. Work on "Geospatial Objects" will yield a set of specifications that are "distributed computing platform" neutral (like the OpenGIS Abstract Specifications) but that can be automatically generated for a specific distributed computing platform using UML tools.

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Frequently Asked Questions (FAQs): 

FAQs - Becoming a Member

Q and A: 
  1. Why should an organization join OGC?
  2. Why should data providers, such as National Mapping Agencies, become involved now instead of waiting for products that conform to the OpenGIS Specifications?
  3. Why should a university become a member of OGC?
  4. Don’t software vendors sacrifice competitive advantage by working in OGC?
  5. Is it possible to evaluate the return on investment (ROI) of participation in OGC?
  6. Is access to information an important justification for participation in OGC?
  7. For whom are OpenGIS Specifications most relevant today?
  8. Has the defense industry played an important role in OGC?
  9. Does involvement in OGC make it possible today to reach new markets? Which ones in particular?
  10. Where do data providers and service providers fit in the technology environment being created by members of OGC?
  11. Has OGC worked with public institutions and other important actors in the geographical information market to promote use of software that conforms with OpenGIS Specifications?
  12. Does membership in OGC help members with their own marketing efforts?
  13. Who will most benefit from this kind of interoperability on the Web?

Q: Why should an organization join OGC?

A: Different kinds of organizations have different reasons to join:

Technology Developers join to:

  • Help drive the interface specifications required for interoperability.
  • Gain early insight into user needs for geoprocessing interoperability.
  • Bring new products and services to market sooner.
  • Reduce development risk and cost, thanks to shared development and industry-wide adoption of open interfaces.

Technology Users join to:

  • Reduce procurement risk and life cycle costs as Standards-based Commercial Off The Shelf (SCOTS) products extend and replace custom-built applications.
  • Guide and accelerate the development and implementation of open interfaces.
  • Encourage broader choice of standards-based geoprocessing solutions in the marketplace.
  • Cooperate and share costs with other user organizations that have similar interoperability needs.

Integrators join to:

  • Gain early opportunity to help enterprises transition from single-vendor and custom-built geoprocessing solutions to solutions offering user choice, rapid integration, online services and extra-enterprise communication and collaboration.
  • Evolve business practices from custom design to enterprise "interface administration."

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Q: Why should data providers, such as National Mapping Agencies, become involved now instead of waiting for products that conform to the OpenGIS Specifications?

A: Construction of new reference architectures for developing, maintaining, distributing and using geospatial information necessarily proceeds bottom-up, from statements of user requirements. Sponsoring OGC Interoperability Initiatives is the best way for data and service-oriented institutions to accelerate this process and to be sure it yields services that meet their needs. Also, by participating in OGC, they become part of the network of technology users and providers that is focused on the same set of problems that concerns the data providers.

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Q: Why should a university become a member of OGC?

A: University researchers in areas related to geoprocessing software development will benefit immensely from technology discussions and projects (live and online) in OGC that involve many of the leading professionals in the field. Also, ongoing OGC projects focused on topics such as sustainable development, disaster management, environment and natural resources provide a focus for research communities that are focused on disciplines other than geoprocessing software development. Many disciplines and many industries are involved. Interoperability unlocks the value of spatial data for interdisciplinary studies. Knowledge gained can be directly applied to many university objectives related to use of geospatial information. Students can help solve important real world problems and make contacts with potential employers. Cost is low. (The cost/benefit ratio of OGC participation is very good compared to other standards activities.)

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Q: Don’t software vendors sacrifice competitive advantage by working in OGC?

A: No, but the competitive environment has changed, so vendor strategies must change. In the past, the comprehensiveness of suites of software provided competitive advantage, and customers became "captive" customers. Now, vendors achieve competitive advantage by offering better open-environment solutions that build on standards. It is still important to offer products that are "best of breed" for specific applications, but products need to interoperate with other vendors’ products. Membership in OGC provides advantages such as access to the specifications, insight into market direction, and efficient access to the voice of the customer. OpenGIS Specifications are becoming the currency for geodata sharing within government and among vertical markets that are impacted by government geoinformation. OpenGIS Specifications provide a data sharing framework by which specialized vendors can integrate into enterprise architectures.

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Q: Is it possible to evaluate the return on investment (ROI) of participation in OGC?

A: Yes. For example, evaluating ROI in terms of dollars, marks, or pounds is possible when an organization considers the value of particular business relationships which would not have become established if the organization had not been active in OGC. Such ROI might be revenue from a major customer or business partner, or savings realized through particular products, services, or business procedures put in place because of what was learned in OGC. It is also possible for a vendor to calculate roughly how much they saved by sharing certain development costs through developing open interfaces collaboratively instead of developing proprietary interfaces in-house. Soon, some product revenues will be clearly attributable to the market value of products’ open interfaces. But it is also true that, in today’s extremely dynamic, complex, and hard-to-predict business environment, many decisions cannot be accurately and promptly evaluated in terms of their contribution to the bottom line. Some evaluations must be more abstract, based on the decision makers’ values, goals, strategies and sense of where the market is going.

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Q: Is access to information an important justification for participation in OGC?

A: Yes, it is one of the fundamental reasons for participation. It is important in terms of access to in-progress specifications, but it is even more important in terms of access to industry trends and developments. This information directly determines the possibilities for industrial and academic research and industrial product strategies.

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Q: For whom are OpenGIS Specifications most relevant today?

A: Initially it was the large government users who become involved because of their critical strategic interest. Major user corporations, such as Telcos and transportation companies, have begun to participate to advance interoperability in their industry domains. But commercial adoption of OpenGIS Specifications in commercial, off-the-shelf products has advanced sufficiently that now all users are affected. At this point, it is critically important for all users of geoprocessing technology to insist on interoperable software products, because the Web's potential is only realized through interoperability.

All software developers and integrators who provide geoprocessing software or who seek to integrate these capabilities into general purpose information systems are also, of course, affected by OpenGIS Specifications.

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Q: Has the defense industry played an important role in OGC?

A: Yes. Defense agencies around the world are major users of GI and GI technology. In the U.S.A. as elsewhere, defense agencies seek to reduce their information system costs by buying Standards-based Commercial Off-the-Shelf (SCOTS) software and data products. OGC provides a great opportunity for them to achieve this. Defense has historically driven funding for national mapping activities, but the long-term payback to society comes through the application of the resultant geographic information, technology and mapping institutions in public, private and academic activities.

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Q: Does involvement in OGC make it possible today to reach new markets? Which ones in particular?

A: Yes, providers are increasingly able to reach non-traditional GIS users and mass markets for GI. Open interfaces enable broad connections to other IT sectors.

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Q: Where do data providers and service providers fit in the technology environment being created by members of OGC?

A: OpenGIS Specifications are specifications for interfaces that enable a variety of services. This is the core of OGC’s work. All geospatial services need geospatial data. In the new paradigm, data providers have a clear opportunity to become service providers, providing services via the Internet. Also, in the new paradigm it makes sense for many providers of data to be the single, authoritative source for that data. Inefficient, redundant data collection will become much less common. There are many payment models available. At the same time, because Web-based computing does not require that data servers and service servers be the same servers, it is likely that many intermediary service providers will find niches in which to operate successfully.

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Q: Has OGC worked with public institutions and other important actors in the geographical information market to promote use of software that conforms with OpenGIS Specifications?

A: Yes, since 1994 OGC has held special meetings for key user organizations, participated in dozens of conferences, provided articles for magazines, mailed informative papers and brochures, and worked to recruit user organizations as members. OGC recognizes the importance of "market pull" in the successful market introduction of interoperable geoprocessing software. This is the mission of OGC's Outreach and Community Adoption Program.

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Q: Does membership in OGC help members with their own marketing efforts?

A: Yes. Technology providers and technology users meet frequently to discuss technical and business issues, and these meetings are very important in the marketing efforts of the technology providers and in the technology users’ development of market awareness.

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Q: Who will most benefit from this kind of interoperability on the Web?

A: Users -- a much larger population of users than currently use GIS and remote sensing software -- will benefit the most. Producers, owners, stewards, and resellers of geodata will also benefit. Software vendors will benefit because: the market will be much bigger; the Web server, tools, and applet markets will be strong; the geoprocessing software integration business will be booming; current users will buy the new versions of software that have OpenGIS Compliant interfaces; and sophisticated and specialized applications will proliferate. There will be new jobs for metadata and data semantics experts, geographers who help build and integrate geographic "content" for Web sites, data coordinators, etc. The Spatial Web will continue to spawn new businesses.

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