OGC Newsroom

Glossary of Terms - I

Definitions: 
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.
imagery
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.
implementation
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.
interface
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.
intermediary
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.
interoperability
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).
IPR
See Interoperability Program Report.
ISO
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.
isolated
Association role between topography primitives and those of co-deminsion 2 or greater. (see OGC Abstract Specification (Topic 1) clause 7.3.10.4)
Glossary: 
OGC Glossary

Glossary of Terms - H

Definitions: 
handle
An index entry or unique name in software that identifies a catalog entry or other resource so that it can be found and utilized by another software facility.
harmonization
With respect to standards: activities undertaken by communities of experts to align standards. For example, to define common metadata and application schema from legacy sources, harmonization will consider: -- Architecture - multiple viewpoints that capture high level requirements, use cases, scenarios, information flows and computational flows. -- Data modelling - definition and UML encoding of feature type, attribute type, data type, coding, dependency mapping -- Schema modelling - UML mapping and encoding to GML, mapping of profiles to one another, and delineation to service types -- Iteration and development - build a little, see if it works, build more- -- Delivery to standards organizations for approval.
hierarchical database
A database that stores related information in terms of pre-defined categorical relationships in a `tree-like` fashion. Information is traced from a major group, to a subgroup, and to further subgroups. Much like tracing a family tree, data can be traced through parents along paths through the hierarchy. Users must keep track of the hierarchical structure in order to make use of the data. The relational database provides an alternative means of organizing datasets.
http
Hypertext Transfer Protocol, the World Wide Web protocol for moving hypertext (HTML) files across the Internet. OGC has defined a suite of Web Service interfaces that have explicit bindings for HTTP. Specifically, there are two HTTP bindings for invoking operations of a service (i.e., Sending a message): GET and POST.
human technology environment
The environment within which people interact with information technology, typically a mouse and windowing system.
human technology interface (HTI)
The interface across which people interact with information technology. The service provided through this interface is access to the information infrastructure and to other people.
hydrography
The charting and description of bodies of water.
Glossary: 
OGC Glossary

Glossary of Terms - G

Definitions: 
gateway service
The Open Location Services (OLS) initiative introduced gateway services, which link location application services (accessed via the Internet or the Web) with mobile wireless-IP platforms, in support of small form factor mobile terminals.
gazetteer
Source: http://www.eurogeographics.org/Projects/GDDD/GDDD/lists/products.htm#52
A catalogue of toponyms (place names) assigned with geographic references. A gazetteer service retrieves the geometries for one or more features, given their associated well-known feature identifiers (text strings).
gazetteer model
The general model for representing online, well-known types of gazetteers.
general feature model
Metamodel of feature types. A feature may have properties that may be operations, attributes or associations. Any feature may have a number of attributes, some of which may be geometric and spatial. A feature is not defined in terms of a single geometry, but rather as a conceptually meaningful object within a particular domain of discourse, one or more of whose properties may be geometric.
general models
Source: The OpenGIS® Abstract Specification Topic 6: The Coverage Type and its Subtypes Version 6. http://www.opengis.org/techno/abstract/00-106.pdf
General Models Define the basic models for how geospatial information is to be characterized and encoded. To date, OGC has defined several types of General Models: (Simple) Feature Model, Coverage Model, Observation Model, Registry Model, Service Model, Data Catalog Model, Dictionary Model, Directory Model, and Gazetteer Model.
geocoder
Transforms a description of a feature location, such as a place name, street address or postal code, into a normalized description of the location, which includes a coordinate geometry.
geocoder Service
Geocoding is the process of linking words, terms and codes found in a text string to their applicable geospatial features, with known positions (i.e., usually a point with x, y coordinates but more generally any geometry), e.g. converting a street address to a geographic location. The Geocoder Service Interface allows for a request providing an address or set of addresses and returns them along with the corresponding geometry (usually a point relative to a requested spatial reference system.) The request is "sent" to a Geocoder Service, which processes the request and returns the resulting geographic feature representing position.
geocoding
Geocoding refers to the assignment of alphanumeric codes or coordinates to geographically reference data provided in a textual format. Examples are the two letter country codes and coordinates computed from addresses.
geodata
Digital data that represent the geographical location and characteristics of natural or man-made features, phenomena and boundaries of the Earth. Geodata represent abstractions of real-world entities, such as roads, buildings, vehicles, lakes, forests and countries. Geodata refers to such data in any format, including raster, vector, point, text, video, database records, etc.
geographic application
Applications which pertain to the Earth and Earth phenomena, with known spatial and temporal reference systems. Expressed in a human context versus computer context.
geographic data
See geospatial data.
geographic feature
Feature associated with a location relative to the Earth. The starting point for modeling of geographic information. A feature is an abstraction of a real world phenomenon. A geographic feature is a feature associated with a location relative to the Earth. A digital representation of the real world can be thought of as a set of features. Geographic features occur at two levels: feature instances and feature types. At the instance level, a geographic feature is represented as a discrete phenomenon that is associated with its geographic and temporal coordinates. These individual feature instances are grouped into classes with common characteristics - feature types.
geographic model
A model of the real world that recognizes an integrated family of spatial features
Geographic Objects
The vision for the Geographic Objects Initiative is to define platform-independent and implementation-neutral interface models of specific geographic services or component objects.
geographic reference system
A 3D reference coordinate system with well-defined origin and orientation of the coordinate axes. A mathematical system.
Geography Markup Language (GML)
OGC`s XML-based language for describing and encoding geospatial information. An application of XML, a specification developed by members of the Open GIS Consortium. http://www.opengis.org/techno/specs/00-029/GML.html ". GML is an XML encoding for spatial data. In a sense, it is a schema-writing language for spatial information.
geometric object
A combination of a coordinate geometry and a coordinate reference system. In general, a geometric object is a set of geometric points.
GeoMobility Server
The open service platform comprising the Core Services developed under the OGC OpenLS initiatives.
geoparser service
Geoparsing refers to the capability to process a textual document and identify key words and phrases that have a spatial context. A Geoparsing Interface implementing this specification works in the context of two bodies of information: a reserved vocabulary (usually of place names, such as a gazetteer) and a text source (e.g., a newspaper, or voice track.) The Geoparser Service returns all occurrences of the use (in the text source) of any word in the reserved vocabulary. Each occasion establishes a geolink between the source and the location associated with the reserved word.
geoprocessing
Use of computers to acquire, analyze, store, display, and distribute information about geographic features. This includes GIS and systems for remote sensing (Earth imaging), facilities management, automated mapping, cartography, navigation, and location services.
geoprocessing applications
Computer applications which model, interpret and use Earth information. The implementation of a Geographic Application on a computer. The terms `geoprocessing,` `geomatics,` and `geotechnology` mean approximately the same thing, though some groups make minor distinctions among them.
georectified gridded data
A cell in a georectified gridded data can be uniquely geolocated, given the cell spacing, grid origin and orientation. Ungeorectified gridded data are irregularly spaced in any geographic/map projection coordinate system. Therefore, the location of one cell in an ungeorectified gridded data cannot be determined based on another cell's location. One approach to rectifying imagery utilizes a sensor description.
georeference
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Description of a location relative to the Earth
geospatial
Referring to location relative to the Earth's surface. "Geospatial" is more precise in many GI contexts than "geographic," because geospatial information is often used in ways that do not involve a graphic representation, or map, of the information.
geospatial data
Location properties related to any terrestrial feature or phenomena. Location properties may include any information about the location or area of, and relationships among, and descriptive information about geographic features and phenomena. This includes remotely sensed data, vector map data, addresses, coordinates, etc. Note that "geospatial data" is more precise in many contexts than "geographic data," because geospatial data is often used in ways that do not involve a graphic representation, or map, created from the data.
Geospatial Fusion Services
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Non-map information - text, video, audio, digital photographs, mpeg movies, sensor data, word processing documents, etc. - often refers to place. Geospatial Fusion Services enable the "fusing" of information such as addresses, place names, coordinates, pinpoints on photographs, and descriptive directions into one information management framework that supports search, discovery, and sharing of spatial information stored in non-map formats.
geospatial information
Information about entities and phenomena that includes their location with respect to the Earth`s surface. Frequently used as a synonym to geodata, but technically, geodata are "dry" digitally represented facts or recorded observations which on their own have no meaning. They become information when interpreted and put in context by humans.
geospatial portal
A Web site that provides a view into a universe of spatial 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. As an open Web resource, a geospatial portal should connect through open interfaces to data and services with similar interfaces. Catalogs and registries that conform to OpenGIS Specifications play an important role in geospatial portals.
GeoTIFF
Data interchange standard for raster geographic images. An extension of the TIFF format to support a geodetically sound raster data georeferencing capability. The aim of GeoTIFF is to allow a means for tying a raster image to a known model space or map projection, and for describing those projections. The geographic content supported in GeoTIFF tag structure includes its cartographic projection, datum, ground pixel dimension, and other geographic variables.
GFS Testbed
OGC`s GFS Testbed yielded a set of candidate standard specifications for open interfaces and protocols that begin to support "geospatial fusion."
GIF
Graphic Interchange Format An image format commonly used on the Web
GII
National Information Infrastructure. The world`s entire collection of public and private digital information, physical networks and network software, computers, and knowledge about how to use them.
GIS
Source: AGI glossary. http://www.geo.ed.ac.uk/agidict/welcome.html
"Geographic Information System. A computer system for capturing, storing, checking, integrating, manipulating, analyzing and displaying data related to positions on the Earth`s surface. " Both vector and raster GISs are available.
GIS application
Source: OpenGIS Guide
"The use of capabilities, including hardware, software and data, provided by a Geographic Information System specific to the satisfaction of a set of user requirements. Example of a GIS application: Spatial decision support system application for district planning purposes."
GISD-ICP
The Geospatial Information for Sustainable Development Initial Capability Pilot (GISD-ICP) is the first of a series of projects to help make geographic information more accessible and useful to decision makers working on sustainable development problems.
Global Spatial Data Infrastructure (GSDI)
A set of policies, standards, practices, technologies, and relationships to facilitate the flow of geographic data and information at all levels across government, academic, and private sectors globally. A linking of National Spatial Data Infrastructures. See www.gsdi.org.
Globe
Source: Wikipedia
A globe is a three-dimensional scale model of Earth (terrestrial globe or geographical globe) or other celestial body such as a planet or moon. While models can be made of objects with arbitrary or irregular shapes, the term globe is used only for models of objects that are approximately spherical.
GML
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
"Geographic Mark-up Language: an application of XML, a specification developed by members of the Open GIS Consortium. http://www.opengis.org/techno/specs/00-029/GML.html ". GML is an XML encoding for spatial data. In a sense, it is a schema-writing language for spatial information.
GML Application Schema
An XML Schema written according to the GML 3 rules for Application Schemas, which defines a vocabulary of geographic objects for a particular domain of discourse
GPS
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Global Positioning System: (1) a network of satellites that interact with special receivers to position the receiver relative to the Earth. (2) describing the generic approach to using a network of satellites to deliver a positioning service. Although GPS can be used to determine location very precisely (within centimeters given the correct controls and proper use, it does not solve all the problems of location determination in GIS databases.
Glossary: 
OGC Glossary

Glossary of Terms - F

Definitions: 
face
2-dimensional topology primitive (see OGC Abstract Specification (Topic 1) clause 7.3.16)
feasibility study
In OGC, a research effort directed at understanding emerging technology areas for the purposes of planning OGC Interoperability Initiatives.
feature
Source: The OpenGIS® Abstract Specification Topic 6: The Coverage Type and its Subtypes Version 6. http://www.opengis.org/techno/abstract/00-106.pdf
The starting point for modeling of geographic information. Abstraction of a real world phenomenon. "A digital representation of a real world entity or an abstraction of the real world. It has a spatial domain, a temporal domain, or a spatial/temporal domain as one of its attributes. Examples of features include almost anything that can be placed in time and space, including desks, buildings, cities, trees, forest stands, ecosystems, delivery vehicles, snow removal routes, oil wells, oil pipelines, oil spill, and so on. Features are usually managed in groups as feature collections. The terms feature and object are often used synonymously. The terms feature, feature collection and coverage are defined in line with OpenGIS."
feature catalog
Source: ISO 19101; ISO 19110
Catalog containing definitions and descriptions of the feature types, feature attributes, and feature relationships occurring in one or more sets of geographic data, together with any feature operations that may be applied
feature collection
Source: OpenGIS Guide
A special category of feature that represents a collection of features that have common metadata and formal relationships. "A set of related features managed as a group. Feature collections can be identified at different abstraction levels, i.e. high abstraction level, e.g. "topography" and low abstraction level, e.g. "roads" The terms feature, feature collection and coverage are defined in line with OpenGIS 5."
feature domain model
The definition (typing framework and properties) of a domain-specific application schema for a well-known class of geospatial features, in vector form (i.e., points, lines and polygons). For example: Transportation, Hydrographic, Electric Utility, etc.
federated database
Separate databases that are structured, perhaps with middleware or special database access software, in such a way that they can be queried as a single database.
find
In the context of OGC Web Services, clients, which might be applications or thin clients on users` computers or which might be other services, find data and services based on what is published in online registries and catalogs. (See Publish.)
framework
An information architecture. In terms of software design, a reusable software template, or skeleton, from which key enabling and supporting services can be selected, configured and integrated with application code.
framework data
In the US, "framework data" or "the Framework" refers to a national collaborative effort to create a widely available source of basic geographic data. It provides the most common data themes geographic data users need, as well as an environment to support the development and use of these data. The framework's key aspects are * seven themes of digital geographic data that are commonly used; (Orthoimagery, Elevation, Transportation, Hydrography, Cadastral, Geodetic Control and Government Units) * procedures, technology, and guidelines that provide for integration, sharing, and use of these data; and * institutional relationships and business practices that encourage the maintenance and use of data. (http://geo-one-stop.gov/participate/status.html)
Glossary: 
OGC Glossary

Glossary of Terms - E

Definitions: 
Earth model
An approach to abstracting the Earth. The data model for the Earth.
edge
1-dimensional topology primitive (see OGC Abstract Specification (Topic 1) clause 7.3.14)
EEA
European Environment Agency
encapsulation
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.
enterprise
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.
EO
Earth observation, i.e., remote sensing.
EOSDIS/HDF
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.
ESDI
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
European Spatial Data Information Infrastructure http://www.ec-gis.org/inspire/
ESPRIT
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
ETeMII
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
Ethernet
A type of local-area network used for high-speed communication among computers.
EUROGI
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.)
extensibility
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: 
OGC Glossary

Glossary of Terms - D

Definitions: 
Data Catalog Model
Source: The OpenGIS® Abstract Specification Topic 6: The Coverage Type and its Subtypes Version 6. http://www.opengis.org/techno/abstract/00-106.pdf
The general model for representing online data catalogs that pertain to enterprise data stores.
data clearinghouse
Source: ISO 19115
Collection of institutions providing digital data, which can be searched through a single interface using a common metadata standard.
data coordination
Organizations that seek to share GI working to reach consensus on common data models.
data domain
Source: GETIS glossary
Set of feature collections that is commonly used in a specific discipline or application. An example of a data domain is {roads, houses, rivers} or on another abstraction level {transport, buildings}
data infrastructure
Source: GETIS glossary
See SDI
data level
Source: ISO 19101
Stratum within a set of layered levels in which data is recorded that conforms to definitions of types found at the application model level
data model
Source: AGI glossary. http://www.geo.ed.ac.uk/agidict/welcome.html
"An abstraction of the real world which incorporates only those properties thought to be relevant to the application at hand. The data model would normally define specific groups of entities, and their attributes and the relationships between these entities. A data model is independent of a computer system and its associated data structures. A map is one example of an analogue data model."
data quality
Source: AGI glossary. http://www.geo.ed.ac.uk/agidict/welcome.html
"Indications of the degree to which data satisfies stated or implied needs. This includes information about lineage, completeness, currency, logical consistency and accuracy of the data"
data schema
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Formal description of a data model
data semantics
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
The meaning of data: in the GI sector this includes the identification of related object classes embedded in different abstractions
data services
OSF services that provide access to collections of data in repositories and databases. Resources accessible by Data Services can generally be referenced by a name (identity, address, etc). Given a name, Data Services can then find the resource. Examples include: Feature Access Services (FAS), Coverage Access Services (CAS) and Sensor Collection Service (SCS).
data transfer
Source: OpenGIS Guide
"In the geoprocessing world, this refers to converting geodata from one (usually proprietary) data format to another. The OpenGIS Specification is not a data transfer standard. Instead, it (in most cases) specifies interfaces by which software systems can exchange information about features, geometry, spatial referencing, and geoprocessing operations. It enables remote GIS systems, for example, to behave like extensions of your local computing environment. "
data transfer standard
A (usually vector) data format designed to be a "lowest common denominator" for multiple data formats, to enable data to be used by different GIS systems.
data update cycle
Source: GETIS glossary
Data update interval
dataset series
Source: ISO 19115; ISO 19113; ISO 19114
Collection of datasets sharing the same product specification
datum
Defines the origin, orientation and scale of the coordinate system and ties it to the earth, ensuring that the abstract mathematical concept 'coordinate system' can be applied to the practical problem of describing positions of features on or near the earth's surface by means of coordinates.
DBF
Data Base File - the dBase file format
DBMS
Database management system. DBMS sometimes refers to the software that contains and organizes the data, and sometimes refers to an organizational plan for the use of information within a single project, or within one unit or the whole of an organization.
DCP
Distributed Computing Platform
de facto standard
Source: OpenGIS Guide
"A standard that has been informally adopted, often because a particular vendor was first to market with a product that became widely adopted. MS-DOS and Microsoft Windows are examples. "
de jure standard
Source: OpenGIS Guide
"An official standard created in a formal `juried` process, such as the International Organization for Standards Technical Committee 211 (ISO TC/211), which is working on problems similar to those addressed by the OpenGIS Specification, but at a higher, more abstract level."
DEM
Digital elevation model, a data exchange format developed by the United States Geological Survey for geographical and topographical data.
DEMTS
Digital and Electronic Maps Transfer Standard. Interchange of digital maps. Russian state standard GOST R*50828-95Â
DGN
DesiGN file, the Microstation drawing format
Dictionary Model
Source: The OpenGIS® Abstract Specification Topic 6: The Coverage Type and its Subtypes Version 6. http://www.opengis.org/techno/abstract/00-106.pdf
The general model for representing online dictionaries that pertain to well-known types of classification schemes and dictionaries.
DIGEST
(Digital Geographic Exchange Standard) Standard that supports images and gridded data in alignment with the ISO/IEC 1/SC 24 BIIF standard. DIGEST Annex D, known as the Image Interchange Format, is an encapsulation of the NATO Secondary Imagery Format (NSIF), which allows for the standard exchange of image, graphic and text data.
Digital Cartographic Model
Source: http://www.eurogeographics.org/Projects/GDDD/GDDD/lists/products.htm#52
"Simple digital maps having a 'flat' data structure, e.g. digitized maps. Digital Cartographic Models (DCMs) are suitable for display and plots purposes. In the context of GIS the DCM may be used as background information. The geometric form of the DCM is vector"
Digital Elevation Model
Source: http://www.eurogeographics.org/Projects/GDDD/GDDD/lists/products.htm#52
"The Digital Elevation Model (DEM) only contains elevation data. Normally, the height data are arranged in a matrix. Also, vector based contour lines and spot elevations are considered as DEM. "
Digital Landscape Model
Source: http://www.eurogeographics.org/Projects/GDDD/GDDD/lists/products.htm#52
"A Digital Landscape Model (DLM) is an object orientated topographic database. The data structure facilitates spatial analysis and linkage of geographic objects to external data. The geometric form of the DLM is vector. The DLM often contains explicit or implicit topological information. The objects, their attributes and the relations between the objects are referred to in terms of real world entities. "
digital orthoimages
Orthorectified images produced using photogrammetric techniques to orthorectify scans of aerial photos and paper maps.
digitize
The process of converting information into the digital codes stored and processed by computers. In geographic applications, digitizing usually means tracing map features into a computer using a digitizing tablet, graphics tablet, mouse, or keyboard cursor.
DIPR
See Draft Interoperability Program Report.
Directory Model
The general model for representing online, well-known types of directories (e.g. Yellow Pages).
directory service
A network-accessible service that provides access to an online directory (e.g. Yellow Pages) to find the location of a specific or nearest place, product or service.
discipline
A particular area of study, such as forestry, hydrology, disaster management, etc. Disciplines often show overlaps in their study topics, data domains and application domains
Discussion Paper
A document containing discussion of some technology or specification area prepared by a SIG or WG for release for the public. Discussion Papers are not the official position of the OGC and contain a statement to that effect.
Distributed Computing Environment (DCE)
DCP being developed by the Open Software Foundation (OSF).
Distributed Computing Platform (DCP)
The foundation technology that enables access to and exploitation of physically distributed information and services. Examples include CORBA, COM/OLE, SQL, Java, and Internet services from the World Wide Web Consortium (W3C) such as HTTP, SOAP and XML.
diversity
The ability of a system or components of a system to support multiple behaviors, functions, and data types.
DLG
Digital line graph, a form of digital map developed by the United States Geological Survey. DLGs supply users with the digital version of information printed on USGS topographical quadrangle maps.
domain
System context: A class of systems that have similar requirements and capabilities. Application context: The body of knowledge defining the range and scope of an application in terms of elements, rules and behaviors.
Draft Interoperability Program Report (DIPR)
A DIPR is an informational report written by participants from an Interoperability Program Initiative. DIPR 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" or "Draft Discussion Paper". The former, obviously, is intended for information only and is not to be considered for public release. The latter, is intended for consideration for public release as a Discussion Paper. A DIPR does not represent the official position of the OGC nor is it an adopted OGC specification.
DTM
Digital terrain model, a method of transforming elevation data into a contoured surface of a three-dimensional display.
DXF
"Drawing eXchange Format", an AutoCad export file. Drawing interchange format, a file exchange format developed by Autodesk Inc. for its AutoCAD drafting software. DXF files are ASCII records of all objects in a drawing file. DXF is used by GIS systems for exchanging map files.
dynamic segmentation
Points along a line that vary in value, e.g. pavement thickness along a road centerline.
Glossary: 
OGC Glossary

Glossary of Terms - C

Definitions: 
CAD or CADD
Computer-aided design and drafting. CAD systems are used to create maps and plans and are closely related to GIS systems. Although most CAD systems lack certain features essential to GIS analysis, such as the power to manage different spatial coordinate systems and database capabilities, many CAD systems have been developed into full GIS with the addition of necessary functions.
cadastral survey
The means by which private and public land is defined, divided, traced, and recorded. The term derives from the French cadastre, a register of the survey of lands and is, in effect, the public record of the extent, value, and ownership of land for purposes of taxation. Cartesian Coordinates are a system of positional reference in which location is measured along two or three orthogonal (perpendicular) axes. Every location can be defined uniquely by its X, Y, and Z coordinates. Locations in the coordinate system can be established using any unit of measurement such as meters, feet, or miles.
Call for Communities
An OGC invitation to local, state, or national government agencies; transnational organizations; academic groups; or private sector companies involved in geospatial technologies to participate in a series of hands-on, collaborative engineering efforts (Pilot Projects) to test the effectiveness of new standards which support Web-based sharing and use of geospatial information.
capabilities document service profile
The result of invoking the "Get Capabilities" operation on a service is a message containing a "capabilities document" describing the service. Provides a high-level description of a service instance and its provider. Includes: a human readable description of the service, a specification of the functionalities that are provided by the service and a set of functional attributes that provide additional information and requirements about the service.
Capabilities XML
Service-level metadata describing the operations and content available at a service
Cartesian coordinates
Coordinates that differ from latitude-longitude coordinates in that the latter comprise a spherical (rather than planar) reference system.
catalog
A collection of entries, each of which describes and points to a feature collection. Catalogs include indexed listings of feature collections, their contents, their coverages, and other metadata. Registers the existence, location, and description of feature collections held by an Information Community. Catalogs provide the capability to add and delete entries. At a minimum Catalog will include the name for the feature collection and the locational handle that specifies where this data may be found. The means by which an Information Community advertises its holdings to members of the Information Community and to the rest of the world. Each catalog is unique to its Information Community.
catalog services
One thing that the OpenGIS Abstract Specification defines is a standard set of services to support on-line catalogs of geodata and geoprocessing capabilities accessible to users in networked environments. Currently, your Web browser can ask a Web indexing service such as Lycos or Alta Vista to report Web sites that contain certain text strings or combinations of text strings. OpenGIS conformant catalog services will enable our Web browser (or other software) to report Web sites (or perhaps non-Web network resources) that contain certain data themes for certain geographic areas for certain time frames. These services will also be able to report geoprocessing resources available on remote servers. Of course, you may not be the one doing the asking. Car computers, for example, will automatically use catalog services to obtain current information about road and traffic conditions.
CEN
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
European Committee for Normalization: makes standards for Europe, cooperates with ISO to avoid competition. http://www.cenorm.be/
centroid
The term given to the center of an area, region, or polygon. In the case of irregularly shaped polygons, the centroid is derived mathematically and is weighted to approximate a sort of `center of gravity.` Centroids are important in GIS because these discrete X-Y locations are often used to index or reference the polygon within which they are located. Sometimes attribute information is `attached,` `hung,` or `hooked` to the centroid location.
CIPI
CIPI is an OGC Interoperability Initiative to help organizations publish, discover, access, exchange, and maintain vital geo-spatial information and online geoprocessing services required to support critical infrastructure protection.
CITE
The OGC Conformance & Interoperability Testing & Evaluation Initiative (CITE) is an OGC Interoperability Initiative designed to test and evaluate OGC Interfaces and products that implement them. The CITE Initiative has three focus areas related to the establishment of a successful and robust OGC Conformance and Interoperability Test and Evaluation Program: * Planning and Feasibility Study, * Conformance Engine, Scripts and Guidelines, and * CITE Portal and Reference Implementations.
classification scheme
An arrangement or division of objects into groups based on characteristics that the objects have in common, e.g., origin, composition, structure, application, function, etc. It is a set of concepts, organized in some specified structure, limited in content by a scope, and designed for assigning objects to classes (concepts) defined within it ISO 11179. It helps to organize the contents of a registry and supports more meaningful queries.
clearinghouse
Source: GETIS glossary
"In general a clearinghouse provides a central access point for value-added topical guides which identify, describe, and evaluate Internet-based information resources. In our case a clearinghouse is a decentralized system of servers located on the Internet which contain field-level descriptions of available digital spatial data. This descriptive information, known as metadata, are collected in a standard format to facilitate query and consistent presentation across multiple participating sites. A clearinghouse uses readily available Web technology for the client side and uses standards for the query, search, and presentation of search results to the Web client. A clearinghouse provides information about who is providing which authorized geoinformation for which application."
client
A software component that can invoke an operation performed by a server.
client/server
The network computing revolution (which includes the distributed geoprocessing revolution) is based on software entities (clients) that tell other software entities (servers) to do things for them. Software clients say, `Send me this specific data from your database!` or `Tell me what Internet address contains this information!` or `Take this data and do a correlation operation on it!` In a simple sense, your word processor is a client when you click on `Save` and the word processor instructs the operating system (acting as a server) to save your file to disk. Interoperability interfaces make it possible for diverse computers to request things of each other over networks and get predictable responses.
COM
"Component Object Model, the Microsoft (MS) paradigm to connect components. MS has implemented the base technology for COM on the NT platform. Software AG has ported these on MVS and UNIX. A COM-object defines its interfaces. Components from different machines can be combined using DCOM ."
Common Object Request Broker Architecture (See: CORBA)
 
Communications Service Interface (CSI)
The interface by which an application platform accesses external entities which provide data transport services. The service provided is data transport among application platforms.
component
In the context of distributed computing, a component is a software program unit that performs one or more functions and that communicates and interoperates with other components through common interfaces.
componentware
Software that exists in relatively small modules with standard interfaces. Components can be combined easily to create tailored applications that are easier to maintain and upgrade than `monolithic` applications that provide the same functionality. Another benefit is that components from different vendors can be used together to provide flexible, economic solutions. componentware can be defined as software products constructed using object technology.
composite curve
Sequence of Curves such that each curve (except the first) starts at the end point of the previous curve in the sequence. (see OGC Abstract Specification (Topic 1) clause 7.3.10.4)
composite map
Two or more maps with the same geographic extent and coordinate reference system can be accurately layered to produce a composite map.
computational viewpoint
Viewpoint in RM-ODP concerned with the functional decomposition of the system into a set of services that interact at interfaces. This viewpoint captures the details of these components and interfaces without regard to distribution. (See the ORM for further definition.)
computer architecture
The functional composition of a system and its components, the interfaces between components, and interfaces with the external environment, including users and other systems.
computer environment
The general term describing the people, hardware, software, and databases comprising a single computer system or several network-connected computer systems, and the associated standards.
conceptual architecture
A diagram and accompanying text that provides a model of how a system works
conceptual schema
Base schema. Formal description of the model of any geospatial information. Application schemas are built from conceptual schemas.
Conformance Test Suite and Guidelines
The set of materials, defined under the OGC Conformance Testing Program document (available at http://www.opengeospatial.org/compliance ), required to test an implementation for conformance to a specification. (Conformance Test Suite and Guidelines refer to OpenGIS Implementation Specifications.) 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 their product conforms to that version of a specification and they can use OGC`s trademarks to assure buyers of the veracity of those claims.
connectivity
A topological property relating to how geographical features are attached to one another functionally, spatially, or logically. In a water distribution system, connectivity would refer to the way pipes, valves, and reservoirs are attached, implying that water could be `traced` from its source in the network, from connection to connection, to any given final point. Functional, spatial, and logical connectivity are examples of relationships that can be represented and analyzed in a GIS database.
container
Association role between topology primitives and those of co-deminsion -2 or greater. (see OGC Abstract Specification (Topic 1) clause 7.3.10.4)
content standard
A standard data model
conversion
The process of transferring data derived from existing records and maps to a digital database. Conversion is a major input problem and can consume the greatest share of time in a GIS project.
coordinate conversion
A mathematical operation on coordinates that does not include a change of datum. The best-known example of a coordinate conversion is a map projection. The parameters describing coordinate conversions are defined rather than empirically derived.
coordinate reference system (CRS)
A coordinate system that has a reference to the Earth. Consists of a coordinate system and a datum.
coordinate system
Composed of a set of coordinate axes with a known metric. The concept 'metric of a coordinate space' consists of the set of mathematical rules that defines the relationships between the coordinate values and the invariant spatial quantities between points; for example, the mathematical rules (formulae) required for calculating angles and distances between points from coordinate values and vice versa.
coordinate transformation
Source: GETIS glossary
A mathematical operation on coordinates that includes a change of datum. The parameters of a coordinate transformation are empirically derived from a dataset containing the coordinates of a series of points in both coordinate reference systems. This computational process is usually "over determined", allowing derivation of error (or accuracy) estimates for the transformation. Also, the stochastic nature of the parameters may result in multiple (different) instantiations of the same coordinate transformation.
coordinates
A tuple of ordered scalar values that define the position of a single point feature in a coordinate reference system. The tuple is composed of one, two or three 'ordinates'. The ordinates must be mutually independent and their number must be equal to the dimension of the coordinate space; for example, a tuple of coordinates may not contain two heights.
CORBA
"Common Object Request Broker Architecture: CORBA is an architecture and specification for creating, distributing, and managing distributed program objects in a network. It allows programs at different locations and developed by different vendors to communicate in a network through an `interface broker.` CORBA was developed under the auspices of the OMG (Object Management Group) and has been sanctioned by both ISO and X/Open as the standard architecture for distributed objects (also known as components)."
The basic distributed object scheme developed by the Object Management Group (OMG), a consortium similar to OGC but focused on object technology instead of distributed geoprocessing. Object Request Brokers (ORBs) help clients find servers.
core technology
The set of Implementation Specifications resulting from the Technology Development process that are based on the Abstract Specification.
coverage
Source: The OpenGIS® Abstract Specification Topic 6: Schema for coverage geometry and functions, Version 7 .
A feature that associates positions within a bounded space (its spatiotemporal domain) to feature attribute values (its range). GIS coverages (including the special case of Earth images) are two- (and sometimes higher-) dimensional metaphors for phenomena found on or near a portion of the Earth's surface. A coverage can consist of a set of features or Feature Collections. Earth images are seen as Grid Coverages that contain features whose geometries are of type "set of cells" or "set of pixels" (surfaces).
coverage domain model
The definition of a domain-specific application schema for a well-known geospatial coverage. For example: DTED.
Coverage Model
Source: The OpenGIS® Abstract Specification Topic 6: The Coverage Type and its Subtypes Version 6. http://www.opengis.org/techno/abstract/00-106.pdf
The basic model for how earth information may be represented as raster or grid coverages (e.g., an image or digital terrain model).
critical infrastructure
Critical infrastructure encompasses large-scale systems in a range of sectors - energy, tele-communications, transportation, public health services, banking, government, public safety etc. These systems are essential to maintaining society.
curve
1-dimensional geometric primitive, representing the continuous image of a line (see OGC Abstract Specification (Topic 1) clause 6.3.16)
curve segment
1-dimensional geometric object used to represent a continuous component of a curve using homogeneous interpolation and definition methods. (see OGC Abstract Specification (Topic 1) clause 6.3.17)
Glossary: 
OGC Glossary

Glossary of Terms - B

Definitions: 
backward (and forward) compatibility
A new version of a standard is backward compatible if all implementation of the new standard include the conformance requirements of the previous versions of the standard.
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.
bind
In the context of OGC Web Services, Bind refers to Web service components connecting and executing through interfaces
BMP
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
broker
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: 
OGC Glossary

Glossary of Terms - A

Definitions: 
Abstract Data Type
The basic information construct used by the GeoMobility Server and associated Core Services. Consists of well-known data types and structures for location information. Defined as application schemas that are encoded in XML for Location Services (XLS).
accuracy
Source: OpenGIS Guide
The degree to which information on a map or in a digital database matches true or accepted values. Accuracy pertains to the quality of data and the number of errors contained in a dataset or map. In discussing a GIS database, it is possible to consider horizontal and vertical accuracy with respect to geographic position, as well as attribute, conceptual, and logical accuracy. The effect of inaccuracy and error on a GIS solution is the subject of sensitivity analysis. Accuracy, or error, is distinguished from precision, which concerns the level of measurement or detail of data in a database.
agent
Source: OpenGIS Guide
A kind of intermediary service which acts on behalf of another service (service provider or requester) according to rules established upon its invocation. Also known as an `intelligent agent.`
Annual Technical Baseline Target
The Annual Technical Baseline Target is the subset of the elements of the Technical Plan that are scheduled to be completed within any given calendar year.
ANSI
An abbreviation for American National Standards Institute. ANSI standards have been established for many elements of computer systems to aid research and development. The existence of standards allows designers to develop general solutions to common problems.
applet
A small application, with limited functionality, designed to operate in a componentware and/or middleware environment. Large, multifunctional, `monolithic` applications can be, and in the future often will be, broken into single-function applets that interoperate with other applets, and that can be assembled, perhaps only temporarily, into a user`s work environment. Java applets, for example, are typically downloaded via the Internet into your computer`s program memory, where they accomplish their task (such as `let the user zoom on this geodata`) and then `evaporate`.
application
Source: OpenGIS Guide
The use of capabilities, including hardware, software and data, provided by an information system specific to the satisfaction of a set of user requirements. See Geographic Application and Geoprocessing Application.
application assembly
Assemble single application from components
application developer
Source: OpenGIS Guide
A software programmer who creates applications, usually by integrating a variety of pre-existing elements such as application programming interfaces and software and hardware platforms.
application domain models
Application-oriented models that characterize information and service resources within a domain. They are often based upon a General Model and must always be consistent with the Abstract Model. The two subclasses are: Data Domain Models and Process Domain Models.
application integration
Integrate multiple applications to support a cross function business process
application platform
Source: OpenGIS Guide
The collection of hardware and software components that provide the infrastructure services used by application programs. APIs make the specific characteristics of the platform transparent and accessible to the application.
application profile
Source:  ISO 19101, ISO 19106
A set of one or more base standards and - where applicable - the identification of chosen clauses, classes, subsets, options and parameters of those base standards that are necessary for accomplishing a particular function.
Application Programming Interface (API)
An interface definition that permits invoking services from application programs without knowing details of their internal implementation.

Application Programming Interface (API)
An interface definition that permits invoking services from application programs without knowing details of their internal implementation.
application schema
A 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. Application schemas are information models for a specific information community.
application services
OWS Services operating on user devices or servers that have network connectivity. Users use Application Services to access Registry, Portrayal, Processing and Data Services. Application Services commonly, but not necessarily, provide user-oriented displays of geospatial content and support user interaction at the user terminal.
application software
Source: OpenGIS Guide
The computing elements supporting users` particular needs. Frequently includes data, documentation, and training, as well as programs.
architectural framework
Source: OpenGIS Guide
Identifies key interfaces and services, and provides a context for identifying and resolving policy, management and strategic technical issues. Constrains implementation by focusing on interfaces, but does not dictate design or specific technical solutions.
architecture
An abstract technical description of a system or collection of systems. Modern software architectures employ interoperability interfaces to enable enterprises and whole industries to establish coherent, flexible, integrated information flows that can be implemented with heterogeneous but intercommunicating software systems. The OpenGIS Specification defines the interoperability interfaces that make it possible to include geographic information in these information flows. Conceptually based, architecture does not contain the level of detail needed for construction.
area of interest
A user defined area (represented by a bounding box, circle or polygon). Often used as a filter in a query.
ASCII
Source: OpenGIS Guide
An abbreviation for American Standard Code for Information Interchange. The ASCII format provides computer systems with a common language for exchanging information. Although most GIS software system make use of proprietary binary codes, almost all systems have import-export capabilities for translating between ASCII and binary formats.
asynchronous
Calling application does not require immediate response to request before proceeding
attribute data
Source: OpenGIS Guide
Descriptive information about features or elements of a database. For a database feature like census tract, attributes might include many demographic facts including total population, average income, and age. In statistical parlance, an attribute is a `variable,` whereas the database feature represents an `observation` of the variable.
Glossary: 
OGC Glossary

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