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 (CORBA)
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.
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)."
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-deminsional geometric primitive, representing the continuous image of a line (see OGC Abstract Specification (Topic 1) clause 6.3.16)
curve segment
1-deminsional 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: 

Glossary of Terms - U

Definitions: 
UDDI
Source: http://www.softwareag.com/xml/about/glossary.htm
"Universal Description, Discovery, and Integration, a standard for a platform-independent, open framework for describing services on the Internet, suggested by, among others, IBM, Ariba and Microsoft, September 6, 2000. UDDI is intended mainly for B2B enhancement and is based on the W3C`s XML standard and, especially on SOAP". UDDI provides a mechanism for clients to dynamically find other Web services. A UDDI registry is similar to a CORBA trader, or it can be thought of as a DNS service for business applications. A UDDI registry has two kinds of clients: businesses that want to publish a service (and its usage interfaces), and clients who want to obtain services of a certain kind and bind programmatically to them.
UML

use case scenario
Source: GETIS glossary
A possible sequence of real world events used as a test case for specifying or testing information systems designed to help manage such events.
user domain
Source: GETIS glossary
"User group with common interests in activities in a specific discipline, parts of a discipline or a type of GIS application, e.g. local government, fire brigades, etc."
user portability
The ability of a user to move from one system to another without having to relearn everything necessary to use such as system.
UTM Coordinate System (Universal Tranverse Mercator)
A planar locational reference system which provides positional descriptions accurate to 1 meter in 2,500 across the entire earth`s surface except the poles. Based on the Universal Transverse Mercator map projection. At the poles, the Universal Polar Stereographic projection is used. The UTM system divides the earth`s surface into a grid in which each cell, excluding overlap with its neighbors, is 6 degrees east to west, and 8 degrees north to south (with the exception of the row from 72-84 degrees north latitude). For any position in the UTM grid, X-Y coordinates can be determined in eastings and northings. Eastings are in meters with respect to a central meridian drawn through the center of each grid zone (and given an arbitrary easting of 500,000 meters). In the northern hemisphere, northings are read in meters from the equator (0 meters). In the southern hemisphere, the equator is given the false northing of 10 million meters.
Glossary: 

Glossary of Terms - N

Definitions: 
National Mapping Agencies
National government agencies, such as the UK's Ordnance Survey, France`s Institut Geographique National (IGN) and the US's US Geological Survey and Federal Geographic Data Committee, that are chartered to provide national mapping products and services.
National Spatial Data Infrastructure (NSDI)
Information Infrastructure elements that make digital geographic information a part of everyone's digital information environment: data content and metadata standards; national Framework (base) data; metadata to help inventory, advertise, and intelligently search geographic data sets; a clearinghouse that allows for catalog searches across multiple geodata servers on the Internet; commercial geoprocessing products that interoperate through interfaces that conform to interoperability interface specifications; and partnerships to advance data sharing and NSDI development.
navigation service
An enhanced version of the Route Service, which is a network-accessible service that determines travel routes and navigation information between two or more points.
NGO
Non-governmental organization
NII
National Information Infrastructure. A nation`s entire collection of public and private digital information, physical networks and network software, computers, and knowledge about how to use them.
NMA
National Mapping Agency
node
0-dimensional topology primitive (see OGC Abstract Specification (Topic 1) clause 7.3.12)
NTF
Neutral Transfer Format. Interchange of geographic information within UK
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: 

Glossary of Terms - R

Definitions: 
raster
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
The representation of spatial data as a matrix of valued cells. Originally, a raster was a scan line in an electronic display such as a television or computer monitor. In geoprocessing, raster refers to a digital representation of the extent of geographic data sets using "grid cells" in a matrix. A raster display builds an image from pixels, small square picture elements of coarse or fine resolution. A raster database maintains a "picture" of reality in which each cell records some sort of information averaged over the cell`s area. The size of the grid cell may range from centimeters to kilometers. Many satellites transmit raster images of the earth`s surface. Reflectance of sunlight at a certain wavelength is measured for each cell in an image.
real-time
Refers generally to systems that respond (almost) immediately or synchronously to external events.
Recommendation Paper
An OGC document containing discussion of some technology or specification area, prepared by a Working Group for release to the public. Recommendation Papers are the official position of the OGC and thus represent an endorsement of the content of the paper.
reference data
European term for a collaborative effort to create a widely available source of basic geographic data, providing national or European coverage of a set of common digital geographic data such as Elevation, Transportation, Hydrography, Cadastral, Geodetic Control, Governmental Units, etc. (Similar to "framework data" in the U.S.)
Reference Implementation
An operational, conformant implementation of an implementation specification, together with available source code, that is made available for public use for testing and development purposes. (a Reference Implementation refers to one or more OpenGIS Implementation Specifications.)
reference model
Provides the complete scientific and engineering contextual framework for a technology area. Includes the underlying elements, rules and behaviors.
register of geodetic points
Source: http://www.eurogeographics.org/Projects/GDDD/GDDD/lists/products.htm#52
"A catalogue of geodetic control points, e.g. trigonometric points and leveling benchmarks."
register of land
Source: http://www.eurogeographics.org/Projects/GDDD/GDDD/lists/products.htm#52
"A general term used for the designation of registers for ownership of land, e.g. cadastre and registers of territorial rights."
Registry Model
The general model for online registries. Sensor Model - The general model for sensor phenomena; the general sensor model for describing well-known sensors.
registry object
Every registered resource is a registry object. Dataset metadata and service metadata are examples of registry objects. All metadata and data types are regarded as registry objects.
registry services
OWS Services that provide a common mechanism to classify, register, describe, search, maintain and access information about resources available on a network. Resources are network addressable instances of typed data or services.
Relational Data Base
Stores data in such a way that it can be added to, and used independently of, all other data stored in the database. Users can query a relational database without knowing how the information has been organized. Although relational databases have the advantages of ease-of-use and analytical flexibility, their weakness can be slower retrieval speed. SQL (structured query language) is an interface to a relational database.
Remote Procedure Call (RPC)
An API for remote (across the network) execution of detailed functions.
remote sensing
Acquisition of raster images of the Earth, often involving spectral frequencies other than the visible band, by devices typically carried on airborne or satellite platforms. Sometimes refers also to image analysis of these images.
reporting group
Source: ISO 19113; ISO 19109
Data with common characteristics forming a subset of a dataset. Note 1: Common characteristics can include belonging to an identified feature type, feature attribute or feature relationship; sharing of data collection criteria; sharing original source; or being within a specified geographic or temporal extent. Note 2: A reporting group can be as small as a feature instance, an attribute value, or a single feature relationship.
request
Invocation of an operation by a client
Request for Comment (RFC)
In the context of OpenGIS Specification Development, an explicit request to the industry for comments concerning a particular technology that an OGC Technical Committee Working Group or Interoperability Initiative is considering for development or adoption as an OpenGIS Specification.
Request for Information (RFI)
In the context of OpenGIS Specification Development, a general request to the industry to submit information to one of the OGC Technical Committee Working Groups.
Request for Proposals (RFP)
In the context of OpenGIS Interoperability Program, an explicit request to the industry to submit proposals for work to be performed as part of an Interoperability Initiative.
response
Result of an operation returned from a server to a client
reverse geocoder service
A network-accessible service that transforms a given position into a normalized description of a feature location (Address with Point), where the address may be defined as a street address, intersection address, place name or postal code
RM-ODP
Reference Model for Open Distributed Processing (ISO/IEC 10746). In RM-ODP, Architecture is defined as a set of components, connections, and topologies defined through a series of views: enterprise, information, computation, engineering and technology.
route service
A network-accessible service that determines travel routes and navigation information between two or more points.
RTD
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Research and Technology Development: a term used in the European IST program.
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: 

Glossary of Terms - V

Definitions: 
validation
The process of testing an application or system to ensure that it conforms to a specification.
vector
A representation of the spatial extent of geographic features using geometric elements (such as point, curve, and surface) in a coordinate space.
vector displays and databases
Databases that build all geographic features from point, that is, from discrete X-Y locations. Lines are constructed from strings of points, and polygons (regions) are built from lines which close.
vector methods
In geoprocessing, methods of representing geographic features from points, lines, and polygons, as opposed to raster techniques which record geographic features within a matrix of grid cells. The choice between vector and raster GIS has much to do with the application being considered since both methods have strengths and weaknesses. Many current GIS permit transformation between vector and raster input and output.
view
SQL `Select`, Statement, used to provide temporary information about a given table(s) of a Database Management System without actually creating a subset or new table.
viewpoint
Form of abstraction achieved using a selected set of architectural concepts and structuring rules, in order to focus on particular concerns within a system. ISO-10746-2 In an RM-ODP based description of a multi-tier, multi-network architecture, the Enterprise, Information, and Computation viewpoints describe a system in terms of its purposes, its content, and its functions.
virtual reality (VR)
Refers generally to interactive multimedia environments that present users with a sensory experience similar in some ways to our experience of the real world.
VPF
Vector Product Format. A published vector format used by the US Department of Defense.
Glossary: 

Glossary of Terms - O

Definitions: 
object
Data and processing functions packaged into a small, discrete, interoperable module. Also, in a specific OGC context, an XML document element of a type derived from AbstractGMLType
Object Oriented (OO)
Software in which data and processing functions are packaged into small, discrete, interoperable modules, offering advantages such as portability and easy maintainability.
object technology
Software scheme in which data and processing functions are packaged into small, discrete, interoperable modules, offering advantages such as portability and easy maintainability.
observation domain model
The definition of a specific observation type in accordance with the general observation model.
Observation Model
The general model for representing observations of earth phenomena; general observation model for describing well-known observations.
OGC
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Open GIS Consortium, Inc. http://www.opengis.org
OGC Interoperability Program
The OGC Interoperability Program provides an industry consensus process to develop, test, demonstrate, and promote the use of standard interfaces and protocols that enable interoperable geoprocessing. The Interoperability Program organizes and manages Interoperability Initiatives, including Testbeds, Pilot Projects, Planning Studies, Insertion Projects, and Feasibility Studies. Technical documents, training materials, test suites, reference implementations and other resources developed in these initiatives become available for use by members and the public on the OGCNetwork.
OGC Network
An OGC web site (http://www.ogcnetwork.org/ ) that provides a Directory of OGC services, fora, mail lists, specifications, discussion papers, Collaborative Test Environment services, and other OGC-related resources.
OGC Specification Program
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 OpenGIS® Specifications for release to the public.
OGC Technical Baseline
See Technical Baseline.
OGC Technical Committee
The OGC Technical Committee is the primary operational unit of the OpenGIS specification development and adoption process. It is comprised of the technical representatives of all OGC member organizations and is charged with creating OpenGIS Specifications and maintaining the OGC Abstract Specification. The Technical Committee does the bulk of its work through its Working Groups (WGs).
OGCE
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Open GIS Consortium (Europe) Limited: a business supporting OGC in Europe. http://www.opengis.co.uk
OLE/COM
Object Linking and Embedding/Common Object Model. A DCP developed by Microsoft.
online
A state (referring to equipment such as computers, plotters, printers, and digitizers) of being turned on and actively communicating with a computer or computer network.
open interface
An interface that implements a standard specification developed in an open consensus process. (See interface.)
Open Location Services
Open Location Services (OpenLS) is a multi-phase project which is focused on defining and building the "core" Location Based Services (LBS) standards and information framework for LBS application services in close coordination with other related industry standards groups.
open platform
In the past, the term platform denoted any specific hardware and operating system combination, such as the Windows/Intel platform. It now used more generally describes an application programming interface (API) or set of APIs that provide access to computing power, database, GIS or other services hidden "underneath" those APIs. The acronym "API" is generally giving way to "interface" in programmer-speak. No single vendor provides an open platform unless all the exposed interfaces are open interfaces as defined above. An open platform needs to be like the IT industry`s Web Services platform, which is still, as of August, 2003, largely unencumbered by proprietary restrictions and is the product of a non-exclusive consensus process.
open source
It is important not to confuse "open source" with "open standards." They are entirely different. The special licenses that govern use and sale of such software exist not to ensure profits to the software`s owner, but to ensure that the software`s source code remains in the public domain (free to all), though companies are allowed to sell products that include some or all of the source code. Open source software is usually developed not by single company but by a distributed team of developers, typically an informal ad hoc group of volunteers.
open specification
A specification that promotes interoperability through its public availability to developers, who use it to develop software or hardware compatible with the common resource described in the specification. Open specifications are generally consistent with related standards and are updated to conform with new standards and new technologies. They may be developed and maintained, as in the case of OpenGIS Specifications, by a public open consensus process.
open standards
An "open standard" is one that: 1. Is created in an open, international, participatory industry process 2. Is freely distributed and openly accessible 3. Does not discriminate against persons or groups 5. Ensures that the specification and the license must be technology neutral: Its use must not be predicated on any proprietary technology or style of interface.
open system
Open systems are systems that interoperate through open interfaces, protocols etc. developed and maintained in an inclusive, open consensus process. Open systems promote application portability, scalability, interoperability, diversity, manageability, extensibility, compatibility with legacy components, and user portability.
open system environment
A computer environment specified by a set of standards and profiles for interfaces, services, and formats for an open system.
OpenGIS Abstract Specification
A document that captures the OGC member consensus on a computing technology independent specification for interfaces, protocols or schemas for interoperable geoprocessing. The Abstract Specification is that part of the OpenGIS Specification created by the OGC Technical Committee to provide a high level description of the functionality to be provided in OpenGIS Implementation Specifications.
OpenGIS Implementation Specification
A document containing a computing platform dependent specification for application program interfaces, protocols etc. OpenGIS Implementation Specifications contain detailed software specifications for implementing standard interfaces, protocols etc. on particular distributed computing platforms such as the Web, SQL, OLE/COM and CORBA.
OpenGIS Reference Model (ORM)
The ORM is a document, part of the OGC Technical Baseline, that provides an overall conceptual framework for building geospatial processing into distributed systems in an incremental and interoperable manner.
OpenGIS Specification
An open software standard developed and adopted in OGC`s open consensus process that enables interoperable geoprocessing, which includes: real-time data sharing and process execution between GIS systems from different vendors; interoperation between dissimilar types of geoprocessing systems (GIS, Earth imaging, surveying and mapping, navigation, etc.); and efficient discovery of and access to remote geodata and geoprocessing resources in distributed computing environments.
OpenGIS, Open GIS and open GIS
OGC registered the trademark "Open GIS" and OpenGIS" in countries around the world to assert the importance of open standards in geoprocessing and to protect these standards with a legal brand. The phrase "open GIS" (with a small "o") is also a trademark of OGC, with the same meaning as "Open GIS," though "open GIS" is not a registered trademark.
OpenLS
See Open Location Services.
OpenLS Core Services
The basic services that comprise the open service platform (GeoMobility Server) defined under OpenLS.
operation
A single step performed by a computer in the execution of a program, or, in the context of object-oriented programming: Specification of an interaction that can be requested from an object to effect behavior. ISO 19119
ORM
OpenGIS Reference Model
orthophoto map
Source: http://www.eurogeographics.org/Projects/GDDD/GDDD/lists/products.htm#52
Digital or digitized aerial photographs in which the pixels are geometrically rectified and given geographical references. The data structure is raster. An orthophoto map may include details of topography and names.
orthorectification
Use of photogrammetric techniques to adjust and correct distortions in mages.
OWS
OGC Web Services.
OWS Service Framework
(OSF) Identifies services, interfaces and exchange protocols that can be utilized by any application. OpenGIS Services are implementations of services that conform to OpenGIS Implementation Specifications. Compliant applications, called OpenGIS Applications, can then "plug into" the framework to join the operational environment.
Glossary: 

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