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Standards, Specifications, and the GeoSpatial Industry
By Dr. Carl Reed This article explores a very active, but for many, little known aspect of our industry: Geospatial Standards and Specifications. Some may consider this topic irrelevant to their operation. Others may simply find it boring. But make no mistake, these long-term, ongoing standards and specifications efforts will impact our industry and shape the way geospatial technology and services are delivered in the future. From my perspective, there are several sources of standards and specifications that impact the geospatial technology and information industry. These are:
• De-facto standards: While not "standards" in terms of being developed and certified by a formal Standards body, these become standards by widespread use in the vendor and user community. The ESRI Shape File format is an example of a de-facto standard.
• Government Standards: These standards are typically developed by a federal government agency. Examples include U.S.G.S. DLG 3 and Department of Defense DTED exchange formats. Some of these formats may be certified by a formal standards body. Nevertheless, being able to read and write to a published government format is usually critical to a company's ability to provide software and/or data to that government.
• Formal Standards: These are standards and/or specifications developed through a formal process as managed by a recognized standards organization. Examples of these types of standards include the OpenGIS¨ Consortium's Simple Feature Access Specification, and the ISO/IEC 12087 specification for imagery.
This article describes the various specifications and standards organizations, their relationships to each other, and their current status. My next article will cover the actual standards and specifications that are relevant to our industry.
The following is a description of the various spatial standards and specifications organizations that may have an impact on our industry. Table 1 shows the various organizations and their overall focus2. The most pertinent standards organizations are then described in greater detail. ISO
Most people are familiar with ISO (International Organization for Standards). Under the ISO umbrella are a number of committees and working groups that have developed, or are developing, standards that impact our industry.
It should also be noted that there is an overarching ISO coordinating group that ties together a number of the spatial standards initiatives. This is called the "Joint Technical Committee 1," or JTC1. This coordinating group seeks to harmonize activities between the ISO and the IEC3 and, through various liaison efforts, the OGC and other organizations. For example, JTC1 helps coordinate such specific efforts as SC 32 (SQL MM), which crosses ISO, IEC, and ANSI boundaries. ISO/TC 211:
TC 211 (http://www.statkart.no/isotc211/) represents an international standards initiative that seeks to:
¥ Standardize digital geographic information
¥ Focus on information concerning objects or phenomena that are directly or indirectly associated with a location relative to the Earth ¥ Specify methods, tools, and services for acquiring, processing, accessing, presenting and transferring geographic information in digital/electronic form
¥ Link to appropriate information technology standards and provide a framework for the development of geographic data applications.
ISO/TC 211 has a number of ongoing activities and is now working closely with the OpenGIS Consortium. TC 211 has representatives from 33 participating countries and 17 observing countries, as well as a number of external observers such as the OGC. They meet as a group several times each year. Progress for the development of published standards has been relatively slow. ISO/TC 204 (http://www.sae.org/TECHCMTE/204.HTM)
ISO/TC 204 focuses on the standardization of information, communications and control systems in the field of urban and rural surface transportation. This includes inter-modal and multi-modal aspects, traveler information, traffic management, public transportation, commercial transportation, emergency services, and commercial services in the transport information and control systems (TICS) field.
ISO/TC 204 is responsible for the overall system aspects and infrastructure aspects of transport information and control systems (TICS), as well as the coordination of the overall ISO work program in this field. Of special interest to our industry are such factors as Working Group (WG) 10 (traveler information systems), WG 9 (integrated transport information, management and control) and WG 16 (wide-area communications, protocols and interfaces). ISO/SC 24 (http://www.bsi.org.uk/sc24/)
ISO/IEC JTC 1/SC 24 is the international standardization committee for computer graphics and image processing. ISO/IEC JTC 1/SC24 is a sub-committee of the Joint Technical Committee 1 of ISO and IEC (ISO/IEC JTC 1). This area of work includes:
• Standardization of interfaces in windowed and non-windowed environments, for computer graphics and image processing
• Interaction with, and visual presentation of, information.
Related areas of interest include: reference models; application specifications; functional specifications; interchange formats; device interfaces; testing methods; registration procedures; and presentation and support for creation of multimedia and hypermedia documents. ISO/IEC JTC1 SC32, Working Group 4, SQL Multimedia and Application Packages
The scope of SC32, WG 4 is to specify packages of abstract data types for use in various application areas. Each package of abstract data-type definitions is specified using the facilities for user-defined type as provided in the Database Language SQL/Foundation. This includes such packages as Full-Text, Spatial, Still Image, Still Graphic, Animation, Full Motion Video, Audio, Seismic, and Music. The URL for SC32 is http://bwonotes5.wdc.pnl.gov/SC32/JTC1SC32.nsf.
The efforts of this Working Group have been encapsulated in the current implementation of SQL/MM, which supports the use of abstract data types for spatial data. The efforts of the SC 32 and the OGC are harmonized primarily through common membership. Open GIS Consortium:
Founded in 1994, the mission of the Open GIS Consortium (OGC - www.opengis.org) involves full integration of geospatial data and geoprocessing resources into mainstream computing, and widespread use of interoperable, commercial geoprocessing software throughout the information infrastructure. The OGC specification process is built on industry consensus. The OGC is not a standards organization per-se. Rather, its focus is on the development of interface specifications for both spatial data and applications. OGC and ISO TC211 have an agreement to sustain the technical alignment of their respective developments. This is accomplished through mutual review and development of draft documents. Whenever an OGC specification meets certain requirements, ISO adopts it as an ISO specification.
The OpenGIS Abstract Specification represents a comprehensive software architecture and abstract model from which specifications can be derived. Interfaces based on this specification will enable true interoperability between clients and applications on desktop computers, servers and/or over networks. Network-resident services based hereon will enable the discovery and use of heterogeneous geodata and geoprocessing resources across distributed heterogeneous environments, such as the Internet.
To date, this process has resulted in a number of interface specifications. However, progress has not been as fast as the membership would like it to be. In order to speed the creation of specifications, the OGC recently instituted the Interoperability Program. Within the Interoperability Program, testbeds are used to define, refine, and test interface specifications. The Web Mapping Testbed was the first of these. During 2000, several new testbed activities will be completed. IETF4
The Internet Engineering Task Force (IETF) is a loosely defined, self-organized group of people who make technical and other contributions to the engineering and evolution of the Internet and its attendant technologies. It is the principal body engaged in the development of new Internet standard specifications. Its mission includes:
• Identifying and proposing solutions to, and pressing operational and technical problems, in the Internet
• Specifying the development or usage of protocols and near-term architecture to solve technical problems for the Internet
• Making recommendations to the Internet Engineering Steering Group (IESG) regarding the standardization of protocols and protocol usage in the Internet
• Facilitating the transfer of technology from the Internet Research Task Force (IRTF) to the broader Internet community
• Providing a forum for the exchange of information within the Internet community among vendors, users, researchers, agency contractors, and network managers.
The IETF is not a traditional standards organization, although it produces many specifications that ultimately become standards. The IETF is comprised of volunteers who meet three times a year to fulfill the IETF mission.
Recently, the IETF instituted BoF (Birds of a Feature) to discuss the formation and mission of a Working Group for location-based services. The OGC has developed an initial working relationship with the IETF. CEN TC 287
CEN is the European Committee for Standardization. Its mission statement is to foster the "implementation of voluntary technical harmonization in Europe in conjunction with worldwide bodies and European partners; and development of procedures for mutual recognition and conformity assessment to standards." In Europe, CEN works in partnership with CENELEC, the European Committee for Electrotechnical Standardization (www.cenelec.be), and ETSI, the European Telecommunications Standards Institute (www.etsi.fr). CEN has a technical relationship with ISO.
Within the CEN family of ongoing activities is TC 287, Geographic Information. This TC has a number of documents that have been prepared by Technical Committee CEN/TC 287, chaired by M. Francois Salg (IGN, France), and adopted as European Pre-standards (ENVs) or CEN Reports (CRs) in 1997 and 1998. ENVs are prospective standards for provisional application in technical fields, where the innovation rate is high or where there is an urgent need for guidance, and primarily where the safety of persons or goods is not involved. It is not imperative that ENVs be adopted by the membership. However, they must be announced and made available to all. The life of an ENV is limited to three years. European Petroleum Survey Group (EPSG)
The European Petroleum Survey Group (EPSG) was formed in 1986. It consists of specialist surveyors, geodesists, and cartographers from European oil companies. Meetings are held twice yearly to discuss survey and positioning topics within those areas of oil industry business, where cooperation is generally agreed to be mutually beneficial.
EPSG has compiled for distribution a set of parameters that define various geodetic and cartographic coordinate systems, thus encouraging standardization across the exploration and production segments of the oil industry (http://www.petroconsultants.com/products/geodetic2.html). The data is included as reference data in the GeoTIFF data exchange specification, in Iris21 (the Petroconsultants data model), and in Epicentre (the POSC data model). Parameters map directly to the POSC Epicentre model v2.2 except for data-item codes, which are included in the files for GeoTIFF and data management purposes, and compound coordinate system data that maps to POSC Epicentre model v3.0.
The EPSG model has been adopted as the foundation of the OGC spatial reference system specification, and is being strongly considered by ISO/TC 211. EPSG has a Class A liaison relationship with ISO/TC 211. World Wide Web Consortium (W3C)
The W3C (www.w3c.org) was founded in October 1994. Its purpose is to lead the World Wide Web to its full potential through the development of common protocols that promote the Web's evolution and ensure its interoperability. It is an international industry consortium, jointly hosted by the Massachusetts Institute of Technology Laboratory for Computer Science [MIT/LCS] in the United States, the Institut National de Recherche en Informatique et en Automatique [INRIA] in Europe, and the Keio University Shonan Fujisawa Campus in Japan. Services provided by the consortium include the following: a repository of information about the World Wide Web for developers and users; reference code implementations to embody and promote standards; and various prototype and sample applications to demonstrate use of new technology. Initially, the W3C was established in collaboration with CERN, where the Web originated, with support from DARPA and the European Commission. For details on the joint initiative and the contributions of CERN, INRIA, and MIT, please see the statement on the joint World Wide Web Initiative.
Location is important to many applications on the Web. Therefore, there are several ongoing activities within W3C that may become very important to our industry. For example, there is considerable discussion on indexing and using 3D/2.5 D data on the Web, as well as how location can be incorporated into the WAP. Web3D Consortium
The Web3D Consortium was formed to provide a forum for the creation of open standards for Web3D specifications, and to accelerate the worldwide demand for products based on these standards through the sponsorship of market and user education programs. Web3D applications have been actively pursued by many organizations for quite some time. This community has spearheaded the development of VRML 1.0 and 2.0 specifications, which provide the basis for the development of associated applications. Organizations involved in this effort felt that the creation of an open consortium, focused exclusively on Web3D, would provide the structure necessary to stabilize, standardize, and nurture this technology for the entire community. Object Management Group (OMG) (www.omg.org)
The Object Management Group (OMG) was founded by eleven separate companies in April 1989. These companies include 3Com Corporation, American Airlines, Canon Inc., Data General, Hewlett-Packard, Philips Telecommunications N.V., Sun Microsystems, and Unisys Corp. The OMG began independent operations as a not-for-profit corporation in October 1989. Through the OMG's commitment to developing technically excellent, commercially viable and vendor-independent specifications for the software industry, the consortium now includes more than 800 members. The OMG is moving forward to establish CORBA as the "Middleware That's Everywhere" through its worldwide standard specifications, CORBA/IIOP, Object Services, Internet Facilities and Domain Interface specifications.
The OMG was formed to create a component-based software marketplace by hastening the introduction of standardized object software. The organization's charter includes the establishment of industry guidelines and detailed object management specifications to provide a common framework for application development. Federal Geographic Data Committee (FGDC)
The FGDC (http://www.fgdc.gov) is an organization that includes the majority of creators and consumers of geospatial data in the U.S. government. The FGDC works to coordinate the many geospatial activities within the federal government, as well as in various outreach programs that engage state and local governments. As part of this work, the FGDC has developed several key standards, such as the FGDC metadata standard, that have been adopted both by industry and by various standards organizations.
The current emphasis of the Federal Geographic Data Committee is to coordinate the development of the National Spatial Data Infrastructure (NSDI). The NSDI encompasses policies, standards, and procedures for organizations to cooperatively produce and share geographic data. The 16 federal agencies that make up the FGDC are developing the NSDI in cooperation with organizations from state, local and tribal governments, the academic community, and the private sector. The FGDC has also provided a number of domain profiles for the Spatial Data Transfer Standard (STDS). These have been done in support of the NSDI and GSDI. Please see http://www.fgdc.gov/standards/status/textstatus.html for a complete listing. Defense and Intelligence (http://164.214.2.59/geospatial/geospatial.html)
Probably the world's largest users and collectors of digital geospatial information are the defense and intelligence communities. While not an official standards body, the U.S. Department of Defense, NIMA, NATO, and other defense organizations have specified a range of Mil-Spec standard formats and compression schemas. The primary U.S. agency to specify these standards is NIMA. These DoD/Intel standards cover vector, imagery, digital elevation and, most recently, video formats. Quite often, the military will make mandatory the requirement to read and write to these specified standards. Defense and intelligence organizations are dedicated to the development and use of specifications and standards. For example, NIMA is very active in TC 211 and the OGC. Simulation Interoperability Standards Organization -SISO (www.sisostds.org)
SISO focuses on facilitating simulation interoperability and component reuse across the Department of Defense, and other government and non-government applications, and seeks to serve the broad Modeling and Simulation (M&S) community by:
• Providing a forum for the interchange of new ideas, concepts, and technology through Simulation Interoperability Workshops
• Educating M&S practitioners and sponsors regarding implementation through tutorials held at the workshops, and through the quarterly publication of an online technical magazine, Simulation Technology
• Supporting the development of standards, practices, and guides for use in various applications.
Within SISO is a sub-group called Synthetic Environment Data Representation and Interchange Specification (SEDRIS). This group focuses specifically on data coding models and spatial reference models for environmental simulation and modeling. Others
And, just when you thought it was safe . . . The list of standards organizations presented thus far is only the beginning. GIS has many sub-specialties, cousins, nephews, and uncles. There are organizations that specialize in:
• Computer-aided design (e.g., The CADD Council) ¥ Architecture (e.g. the National Institute for Building Sciences)
• Facility management (e.g. the Tri-Service Spatial Data Standard)
And there are others in such disciplines as surveying, utility management, urban modeling, resource management, agriculture, weather, oceanography, geology, mining, ecology, and so on. Conclusion
There are many standards organizations that deal with spatial data and technology. At times they work at cross-purposes. Therefore, just this past February, Martin Ford convened a special meeting called the "ISO/IEC JTC1 Special Group on Spatial." The focus of this meeting was "Planning Spatial Standardization and Related Interoperability." In attendance were representatives from most of the standards and specifications groups discussed in this article. The goal of these attendees was to develop responsibilities for work in spatial standardization and related interoperability. Their primary focus was to achieve minimal overlap and optimum collaboration. A second meeting will be held this May.
What will be the net result of all these standards and specifications efforts? It appears that only time will tell. However, please consider that a number of large government agencies are drafting procurement language specifying the use of OpenGIS¨, as well as other specifications. And, as I write this, a number of GIS vendors are enhancing their offerings to further support new and emerging standards and specifications. Acknowledgements
1 Thanks to Cliff Kottman for reviewing and commenting on this article. Also, the geospatial standards and specifications world is constantly changing, I have tried to capture the current state as accurately as possible. My apologies if I have missed a key initiative or have misrepresented the activities or missions of any of the organizations mentioned in this document. Readers' comments are welcome.
2 Derived from a table presented by Henry Tom of Oracle, at the GI Standards Summit in December 1999.
3 International Electrotechnical Commission
4 This description of the IETF was extracted from their web site (www.ietf.org). About the Author:
Dr. Carl Reed, director of information technology at Image Matters, may be reached via e-mail: [email protected] Dr. Carl Reed is currently an independent consultant specializing in working with both the commercial and government sectors to bring geospatial knowledge into business processes. Dr. Reed also represents Intergraph as their director of geospatial business development. Previously, he was vice president of geospatial marketing at Intergraph Corporation. Reed joined Intergraph in April 1998, after a long tenure at Genasys II, where he most recently served as chief technology officer for Genasys II worldwide. From 1989 to 1996, Reed was president of the Genasys U.S. operation. Prior to that, he was system architect for the team that designed and developed the Genasys product suite. Reed has been an active member of the OpenGIS Consortium since 1994. Before his tenure at Genasys, Reed worked at Autometric for six years as GIS division manager, developing a variety of systems for the civilian branches of the U.S. federal government as well as for the military. Reed worked on such programs as Terrain Analysis Work Station, the cruise missile program, Computer Assisted Photo Interpretation Research, and the Mark 90 proposal effort (the first NIMA modernization program). Prior to his work at Autometric, Reed worked for the U.S. Fish and Wildlife Service, developing an interactive GIS for environmental mitigation. The result of this work was a system called the Map Overlay and Statistical System (MOSS). This was the world's first full-function, interactive vector-based GIS to run on a mini computer. At one time, MOSS was used by dozens of federal agencies. Reed received his PhD in Geography in 1978, specializing in GIS technology, from the State University of New York at Buffalo. Since beginning graduate school in 1972, Reed has published dozens of professional papers, delivered hundreds of seminars, and spoke on numerous conference panels. In 1996, in recognition of his contribution to the GIS industry, Reed was voted by his peers as one of the top ten most influential people in GIS.
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