OGC Glossary

Glossary of Terms - E

Earth model
An approach to abstracting the Earth. The data model for the Earth.
1-dimensional topology primitive (see OGC Abstract Specification (Topic 1) clause 7.3.14)
European Environment Agency
In object-oriented programming, data can be encapsulated in an object, which means all access to the data and manipulation of the data occurs through the object`s methods. Legacy software or data can be encapsulated by giving it an interface that is compatible with object software.
engineering viewpoint
RM-ODP viewpoint that relates a system`s purposes, content, and functions to specific components linked by a communications network. This viewpoint is concerned primarily with the interaction between distinct computational objects: its chief concerns are communication, computing systems, software processes and the clustering of computational functions at physical nodes of a communications network. The engineering viewpoint also provides terms for assessing the "transparency" of a system of networked components - that is, how well each piece works without detailed knowledge of the computational infrastructure. The engineering viewpoint can be described in terms of UML collaboration diagrams and deployment diagrams.
In the context of computing, an enterprise is a large organization whose many offices, agencies, workers and partners must be able to communicate and share information effectively and efficiently.
enterprise application
Software that automates a business process that spans many business units
enterprise viewpoint
Describes the business or organizational perspective, context, purpose, scope and policies governing a distributed information system. The ORM enterprise viewpoint highlights geospatial location as a fundamental information ingredient and provides a representative value chain of geospatial information within an enterprise or an information community. The ORM enterprise viewpoint includes the major requirements on OGC technology as derived from the described value chain.
Earth observation, i.e., remote sensing.
HDF-EOS is an extension of NCSA (National Center for Supercomputing Applications) Hierarchical Data Format. HDF-EOS adds mechanisms for storing geo-referencing and temporal information, data organization, and metadata storage. HDF-EOS contains Grid, Point and Swath structures.
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
European Spatial Data Information Infrastructure http://www.ec-gis.org/inspire/
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
The Research programme of the European Union until 1998 http://www.cordis.lu/esprit/home.html
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
European Territorial Management Information Infrastructure: a Fifth Framework project supporting consensus-building on Data issues. http://www.ec-gis.org/etemii
A type of local-area network used for high-speed communication among computers.
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
European Umbrella Organisation for Geographic Information: members are national associations (e.g. The Association for Geographic Information in the UK) and related pan-European sector bodies. http://www.eurogi.org/
exemplar implementation
An operational, conformant implementation of an implementation specification that is made available for public use for testing purposes (Exemplar Implementations refer to OpenGIS Implementation Specifications.)
The ability for a system or components of a system to expand by assimilating new data, software or hardware components.
extrinsic resource
A registered resource associated with a repository item for which the content model is not defined by the RIM. It may be located in a repository not managed by a Registration Authority, and its content may be represented by any Internet Media Type (e.g. application/pdf, image/svg+xml).

Glossary of Terms - W

World Wide Web Consortium. The organization that manages standards for the Worldwide Web.
Web Coverage Service (WCS)
Supports the networked interchange of geospatial data as "coverages" containing values or properties of geographic locations. Unlike the Web Map Service, which returns static maps (server-rendered as pictures), the Web Coverage Service provides access to intact (unrendered) geospatial information.
Web Feature Service (WFS)
OpenGIS Specification that supports INSERT, UPDATE, DELETE, QUERY and DISCOVERY of geographic features. WFS delivers GML representations of simple geospatial features in response to queries from HTTP clients. Clients access geographic feature data through WFS by submitting a request for just those features that are needed for an application.
Web mapping
Dynamic query, access, processing, combination and portrayal of different types of spatial information over the Web.
Web Mapping Service (WMS)
OpenGIS Specification that standardizes the way in which Web clients request maps. Clients request maps from a WMS instance in terms of named layers and provide parameters such as the size of the returned map as well as the spatial reference system to be used in drawing the map.
Web Mapping Testbeds (WMT) Phases 1 and 2
The groundbreaking Web Mapping Testbed Phase 1 (WMT 1), which ran from June, 1999 to October, 1999, yielded candidate interface specifications for Web mapping that were subsequently approved by OGC`s Technical Committee and Planning Committee. The Web Mapping Testbed Phase 2 (WMT 2), which ran from June, 2000 to March, 2001 expanded on this foundation with extensions to those specifications and a set of new draft specifications
Web Registry Service
The Web Registry Service is a software component that supports the run-time discovery and evaluation of resources such as services, datasets, and application schemes.
Web Service Flow Language (WSFL)
Available at: www.oasis-open.org/cover/wsfl.html
Web Services
"Web services are self-contained, self-describing, modular applications that can be published, located, and invoked across the Web. Web services perform functions that can be anything from simple requests to complicated business processes. Once a Web service is deployed, other applications (and other Web services) can discover and invoke the deployed service."
Web Services Definition Language (WSDL)
Available at: http://www.w3.org/TR/wsdl
Web Services Description Language (WSDL)
The language for describing and encoding services. The Web Services Description Language (WSDL) is a draft specification from W3C to describe networked services in terms of what they can do, where they reside on the network and how to invoke them.
Well-Known Binary Representation for Geometry (WKBGeometry)
Data format that provides a portable representation of a Geometry value as a contiguous stream of bytes. Obtained by serializing a geometric object as a sequence of numeric types drawn from the set {Unsigned Integer, Double} and then serializing each numeric type as a sequence of bytes using one of two well defined, standard, binary representations for numeric types (NDR, XDR).
Well-Known Text Representation of Spatial Reference Systems
Format that provides a standard textual representation for spatial reference system information. The definitions of the well-known text representations are modeled after the POSC/EPSG coordinate data.
See Web Feature Service.
See Web Map Service
WMS Context
XML document that unambiguously describes the state or "context" of a WMS client states that accounts for a specific grouping of one or more maps from one or more map servers can be described in a portable, platform-independent format for storage in a repository of for transmission between WMS clients
Working Group (WG)
In OGC, a group of individuals composed of members of the Technical Committee and invited guests, working to solve some particular problem or problems in a particular arena of interoperable geoprocessing. A particular use of the Working Group structure is to generate Requests for Information or Requests for Proposal, and to evaluate responses.
See Web Registry Service.
Web Services Description Language
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
"World Wide Web: a collection of protocols, based on IP, and infrastructure that enable efficient, user-friendly publishing, discovery and access to digital information."

Glossary of Terms - P

Portable Document Format. An Adobe file format readable with free software (Acrobat Reader)
Use of aerial photographs to produce planimetric and topographic maps of the earth`s surface and of features of the built environment. Effective photogrammetry makes use of ground control by which aerial photographs are carefully compared and registered to the locations and characteristics of features identified in ground-level surveys.
pilot project
In the context of the OGC Interoperability Program, a project to introduce new technology products into an operational environment to discover the effectiveness of these products and the new approaches they enable, and to provide feedback into the Specification Program.
Planning Committee
The OGC Planning Committee identifies market opportunities for interoperability and uses this information to document and maintain a "Technology Roadmap" that sets forth the plan, schedule and rationale for OGC activities.
planning study
In OGC: Strategic study that assesses opportunities to expand and sustain an organization's interoperability capacity.
Another term for computer hardware, including microcomputers, workstations, and mainframe computers, or for underlying software, like an operating system, that provides services to layered software.
platform independent
Depends on context, but in general, when discussing software, platform independence means the software can be run on any computer or operating system or distributed computing platform.
Portable Network Graphic. A format for Web graphics
point of interest
A location (with a fixed position) where one can find a place, product or service, typically identified by name rather than by address and characterized by type, which may be used as a reference point or a target in a location based service request, e.g., as the destination of a route.
point to grid interpolation
Source: GETIS glossary
The conversion from a geospatial data set that represents a surface with points and their attributes (e.g. terrain heights) to a grid (raster) data structure that represents the same surface. The estimation of attribute values of the surface at an unsampled point in the grid is based on the known attribute values of surrounding points in the point dataset.
Source: AGI glossary. http://www.geo.ed.ac.uk/agidict/welcome.html
A feature used to represent areas. A polygon is defined by the lines that make up its boundary and a point inside its boundary for identification. Polygons have attributes that describe the geographic feature they represent.
polygon overlay
Source: AGI glossary. http://www.geo.ed.ac.uk/agidict/welcome.html
"The process of superimposing two or more polygons, through registration to a common co-ordinate system. Such an overlay procedure determines the spatial coincidence of two sets of polygon features and creates a new set of polygons based upon overlay operating."
A Web site that provides a view into a universe of content and activity through a variety of links to other sites, communication and collaboration tools, and special features geared toward the community served by the portal.
The presentation of information to humans, e.g., a map. In the context of the Web, portrayal refers to how data is presented for the user. Map portrayal, for example, is concerned with shape and color of symbols representing features, rules for displaying text labels, rules for showing/not showing symbols based on zoom extent, etc.
Portrayal Service
Defines a standard interface for producing visual pictures from coverage data. CPS extends the WMS interface and uses the Styled Layer Descriptor (SLD) language to support rendering of WCS coverages. provide visualization of geospatial information. Portrayal Services are components that, given one or more inputs, produce rendered outputs (e.g., cartographically portrayed maps, perspective views of terrain, annotated images, views of dynamically changing features in space and time, etc.). Examples include: Map Portrayal Services (MPS), Coverage Portrayal Services (CPS) and Mobile Presentation Services.
Refers to the level of measurement and exactness of description in a GIS database. Precise locational data may measure position to a fraction of a unit. Precise attribute information may specify the characteristics of features in great detail. It is important to realize, however, that precise data - no matter how carefully measured - may be inaccurate. Surveyors may make mistakes or data may be entered into the database incorrectly. Therefore, a distinction is made between precision and accuracy.
presentation (map portrayal) service
A network-accessible service that portrays a map made up of a base map derived from any geospatial data and a set of ADT's as overlays.
process domain model
Data model that characterizes well-known, domain-specific business processes. These models capture business rules, policies, tasks, and procedures in the form of processing chains. Microsoft, IBM and others are collaborating on a standard methodology for online workflow and service chaining. When this standard stabilizes and emerges, organizations will start testing this technology and adapt it in a wide range of workflows. When that happens, many Process Domain Models will result.
processing services
OWS Services that operate on geospatial data and provide 'value-add' services for applications. They can transform, combine, or create data. Processing Services can be tightly or loosely coupled with other services, such as Data and Portrayal Services. Processing Services can be sequenced into a 'chain' of services to perform specialized processing in support of information production workflows and decision support. Examples include: Coordinate Transformation Services (CTS), Geocoder Services, Route Determination Services etc.
A collection of standards, with parameters, options, classes, or subsets, necessary for building a complete computer system, application, or function. An implementation case of a more general standard or set of standards.
A facet or attribute or an object referenced by a name.
A set of semantic and syntactic rules that determine the behavior of entities that interact.
In the context of the OGC Interoperability Program, prototyping refers to developing a new candidate standard interface, protocol, schema etc. for the purpose of learning about it and guiding future OpenGIS Specification development.
In the context of OGC Web Services, just as non-spatial Web pages "publish" their contents - make them discoverable - through HTML, metadata, geodata and geoprocessing services servers publish their contents and capabilities through XML metadata contained in feature type registries, feature instance catalogs, and service registries.
publish, find, bind
In the context of Web Services, publish means to advertise data and services to a broker (such as registry, catalog or clearinghouse). A service provider contacts the service broker to publish (or unpublish) a service. A service provider typically publishes to the broker metadata describing its capabilities and network address. Find is used by service requestors to locate specific service types or instances. Service requestors describe the kinds of services they're looking for to the broker and the broker responds by delivering results that match the request. Service requestors typically use metadata published to the broker to find service providers of interest. Bind results after a service requestor and a service provider successfully negotiate so the requestor can access and invoke services of the provider. A service requestor typically uses service metadata provided by the broker to bind to a service provider. The service requestor can either use a proxy generator to generate the code that can bind to the service, or can use the service description to manually implement the binding before accessing that service.

Glossary of Terms - I

image metadata
XML encoding used to describe all types of images handled by OpenGIS Framework services. Image Metadata is used for publishing and discovery of types of original and derived images, image identifications, dates, spatial extents and other information that could be used to find and retrieve images from an archive.
A common way of collecting information associated with a coverage, by which the value of a continuous phenomenon is usually sampled at regular but discrete locations, i.e. pixels.
A software package that conforms to a standard or specification. A specific instance of a more generally defined system.
implementation profile
An Implementation Profile contains an interoperable set of implementation technologies. The languages and associated technologies that a functioning enterprise depends upon are part of the Implementation Profiles for an environment. In addition to modeling languages, Implementation Profiles contain inter-process communication protocols and other dependent infrastructure technologies that the framework employs.
implementation specification
Guidance for software engineers that is so specific that any two independent software implementations of the specification can "plug and play" for each other.
implementation view
Part of Information Viewpoint that captures how information must be represented within a working enterprise (i.e., how it is encoded for runtime use).
information appliance
End-user equipment having input and display (or auditory) capabilities for communication with other users or service providers in the NII.
Information Community
Source: The OpenGIS® Abstract Specification Topic 6: The Coverage Type and its Subtypes Version 6. A collection of people (a government agency or group of agencies, a profession, a group of researchers in the same discipline, corporate partners cooperating on a project, etc.) who, at least part of the time, share a common digital geographic information language and common spatial feature definitions. See Topic 14, Semantics and Information Communities.
Information Storage Interface (ISI)
The interface across which information technology interacts with external storage media. The service provided through this interface is persistent storage of data, where the physical storage media is often removable.
integrated client
A software application that provides a unified environment for visualizing, analyzing, and editing geospatial data from a wide variety of sources.
A named set of operations that characterize the behavior of an entity. An implementation of operations including the syntax of the interaction for a given distributed computing technology. A shared boundary between two functional entities. An established ordering of parameters (with specific names and data types) and instructions (with specific names and functions) that enables one software component to exchange data and instructions with another software component.
A service that provides functions by which to interconnect, adapt and facilitate services offered by other parties, components or environments. Common forms of intermediaries include agent, broker, mediator and trader services.
Source: OpenGIS Guide
Capability to communicate, execute programs, or transfer data among various functional units in a manner that requires the user to have little or no knowledge of the unique characteristics of those units ISO 2382-1. "The ability for a system or components of a system to provide information portability and interapplication, cooperative process control. Interoperability, in the context of the OpenGIS Specification, is software components operating reciprocally (working with each other) to overcome tedious batch conversion tasks, import/export obstacles, and distributed resource access barriers imposed by heterogeneous processing environments and heterogeneous data. "
Interoperability Program
The OGC Interoperability Program is a global, collaborative, hands-on engineering and testing program designed to deliver proven candidate specifications into the OGC Specification Development Program and to exercise and test existing OGC Implementation Specifications in domain specific situations.
Interoperability Program Report (IPR)
An IPR is provided by an Interoperability Program Initiative to the TC. IPR documents may be submitted to the OGC TC for review and comment. Depending on the desired outcome, the document type should be either "Information-Only", "Draft Discussion Paper", "Draft Recommendation Paper", or "RFC Proposal". The first, obviously, is intended for information only and is not to be considered for public release. The second approach is intended for consideration for public release as a Discussion Paper. The third is intended for consideration for public release as a Recommendation Paper. The last is intended for consideration as an RFC proposal (and must be submitted under the TC Policies and Procedures for RFCs). An IPR is not a publicly available document. An IPR will be provided to the TC in the correct IPR template format. An IPR does not represent the official position of the OGC nor of the OGC Technical Committee.
intrinsic resource
A registered resource for which the content model and normative representation are defined by the Registry Information Model (RIM).
See Interoperability Program Report.
International Organization for Standardization
ISO 19108, GI - Temporal Schema
See http://www.statkart.no/isotc211/scope.htm#19108 for a brief description.
ISO 19118, GI - Encoding,
See http://www.statart.no/isotc211/scope.htm#19118 for a brief description.
ISO/CD 19107.3, GI - Spatial Schema
See http://www.statkrt.no/isotc211/scope.htm#19107 for a brief description.
ISO/CD 19115 (ISO TC 211 N 1024, 201-01-30) GI - Metadata
See http://www.statkart.no/isotc211/scope.htm#19115 for a brief description.
ISO/CD 19119 (ISO TC 211 N 1044, 2001-01-29) GI - Services
See http://www.statkart.no/isotc211/scope.htm#19119 for a brief description.
Association role between topography primitives and those of co-deminsion 2 or greater. (see OGC Abstract Specification (Topic 1) clause

Glossary of Terms - B

backward and forward compatibility
Interoperability with earlier and la
base document
The working draft of the OpenGIS Specification, maintained by the Chairman of the OGC Technical Committee, which is the repository for working papers that have been submitted by Committee members.
base maps, data, or layers
Spatial data sets that provide the background upon which more specific thematic data is overlaid and analyzed. As inputs into a GIS, the term base map is usually applied to those sources of information about relatively permanent features including topography, soil data, geology, cadastral divisions, and political divisions. Within a GIS database, such information may become part of a land base to which other information is indexed and referenced.
base standard
An approved International Standard, Technical Report, CCITT Recommendation or National Standard.
In the context of OGC Web Services, Bind refers to Web service components connecting and executing through interfaces
Bitmap. A Microsoft Windows image format.
bounding box
a set of 2, 4, 6 or 8 numbers indicating the upper and lower bounds of an interval (1D), rectangle (2D), parallelpiped (3D), or hypercube along each axis of a given CRS
A kind of intermediary service whose responsibility is only to bring other services together (typically a service requester and a service provider) and has no responsibility for satisfactory completion of the `contract` established between the requester and provider.
business object
An identifiable business concept such as customer or order.
business process
See process domain model.

Glossary of Terms - T

Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Technical Committee within ISO for Geographic Information/ Geomatics standards
Technical Baseline
The OGC Technical Baseline, at any point in time, 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.
Technical Committee
In the OGC Specification Program, the OGC Technical Committee reviews specifications for interfaces and encodings developed either in the Interoperability Program by groups of members, or through an internal proposals process. The Technical Committee and Planning Committee then approve these as "adopted" OpenGIS® Specifications for release to the public. The OGC Technical Committee is comprised of the technical representatives of all OGC member organizations. The Technical Committee does the bulk of its work through its Working Groups.
Technical Plan
The OGC Technical Plan, at any point in time, is the set of planned modifications and additions to the Technical Baseline that could occur over a given time horizon. This includes both the specification documents as well as the Supporting Material.
Technology Insertion Project
In OGC: Collaborative project focusing on expanding an organization's interoperability capacity by laying the infrastructure (groundwork) for open implementations.
technology viewpoint
RM-ODP viewpoint concerned with the underlying infrastructure in a distributed system. It describes the hardware and software components used in a distributed system. The infrastructure, which may be provided by a Distributed Computing Platform (DCP), allows objects to interoperate across computer networks, hardware platforms, operating systems and programming languages.
temporal reference system
The temporal reference system package in the ORM provides elements for describing temporal reference systems, e.g., calendars and clocks.
In the context of OGC's Interoperability Program, a testbed is a collaborative activity in which sponsors provide interoperability requirements and financial support and technology providers team to develop prototype interoperability interfaces, protocols etc. that meet those requirements. The testbed concludes with a public demonstration, and the prototype-derived specifications are submitted to the OGC Technical Committee for review and approval.
thematic map
A map showing, by color or pattern, the distribution of a single phenomenon
thick clients
Clients that handle much of the necessary computation and data/metadata management themselves; and rather than invoking the processing services of other components, they obtain their inputs through low-level data-access requests.
thin clients
Clients that rely on invoking the services of other components (servers, middleware) for most of the computation they need to function in the system; they also rely on other components to manage most of the data and metadata they use.
Tagged Image File Format. A graphic file format developed by Aldus and Microsoft.
Topologically integrated geographic encoding and referencing file. This is a type of digital map developed by the U.S. Bureau of the Census to support the 1990 population census. Census maps in TIGER format succeed the previous DIME format. TIGER files are available for every county in the United States and for the millions of census blocks in urban areas. Although the accuracy of TIGER files varies from county to county, partly for reasons beyond the control of the Bureau, they are likely to improve in coming decades. The TIGER files are a particularly important resource for many urban GIS. The Census Bureau is moving to provide TIGER data in GML.
tightly coupled data and service
An instance of a service associated with a specific instance of a dataset.
Calling application must have detailed knowledge of interfaces of called application. Call is likely made in same technology, and using same call structure.
A software component, sometimes called an application object, which can act as either a service provider or service requester within an application platform.
topographic map
Source: AGI glossary. http://www.geo.ed.ac.uk/agidict/welcome.html
"A map whose principal purpose is to portray the features of the earth`s surface. These features might include the cultural landscape, but normally refer to the terrain and its relief."
Properties of geometric forms that remain invariant when the forms are deformed or transformed by bending, stretching, and shrinking. Among the topological properties of concern in GIS are connectivity, order, and neighborhood. One productive use of topology is to accelerate computational geometry. Geometric calculations such as containment (point-in-polygon), adjacency, boundary, and network tracking are computationally intensive. For this reason, combinatorial structures known as topological complexes are constructed to convert computational geometry algorithms into combinatorial algorithms. Another purpose is, within the geographic information domain, to relate feature instances independently of their geometry.
A kind of intermediary service which acquires services from one or more providers for `resale` to a service requester. The trader service insulates requester and provider services from having to interact directly with one another. The trader is responsible to the requester for all aspects of the requested service.
transfer protocol
Source: ISO 19118
Common set of rules for defining interactions between distributed systems.
The process of converting data or commands from one computer format to another, or from one computer language to another.
The ability of systems or components of systems to hide the details of their implementations from other client or server systems or components of systems.
An ordered set. Such a set of coordinates that define a point.