OGC Glossary

Glossary of Terms - V

The process of testing an application or system to ensure that it conforms to a specification.
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.
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.
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.
Vector Product Format. A published vector format used by the US Department of Defense.

Glossary of Terms - O

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.
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).
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
Object Linking and Embedding/Common Object Model. A DCP developed by Microsoft.
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.
See Open Location Services.
OpenLS Core Services
The basic services that comprise the open service platform (GeoMobility Server) defined under OpenLS.
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
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.
Use of photogrammetric techniques to adjust and correct distortions in mages.
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 of Terms - H

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.
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.
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.
The charting and description of bodies of water.

Glossary of Terms - A

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).
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.
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.
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.
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`.
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.
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.
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.
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 of Terms - S

Spatial Archive and Interchange FormatÂ
The ability to change the component configuration of a system to fit desired application contexts.
scanned map
Source: http://www.eurogeographics.org/Projects/GDDD/GDDD/lists/products.htm#52
Analogue maps digitized by scanning. The data structure of scanned maps is raster.
A structured framework. A metadata schema specifies the order and types and labels of information elements describing a geodata set.
Standards based commercial off-the-shelf software. ("Off the shelf" means that the product is commercially available, without any need for customization.)
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
"(Geo)Spatial Data Infrastructure: a comprehensive package of consensus and initiatives required to enable complete provision of data, access and privacy within the territory of the designated infrastructure."
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Standards Development Organization: any international organization that develops standards for the whole community. Includes de jure SDOs and standards consortia.
Spatial Data Transfer Standard. A standard vector format developed by the US Federal Geographic Data Committee.
semantic translator
A collection of mappings between a target Information Community`s data model and a source Information Community`s data model, generally held and maintained by the target Information Community, though both Information Communities may participate in configuring it. Usually expressed in terms of metadata, features, attributes and rules that permit information integration to occur when a feature collection is imported to the target Information Community from a source Information Community.
Sensor Collection Service (SCS)
Provides a web-enabled interface to a sensor, collection of sensors or sensor proxy. The Sensor Collection Service provides a standard interface for clients to collect and access sensor observations and manipulate them in different ways. SCS instances are collection points on the web for disparate types and instances of sensors. SCS instances deliver sensor observation values (e.g., temperature, ppm, chemical type) in response to queries form HTTP clients.
sensor domain model
The definition of a specific sensor type in accordance with the general sensor model.
Sensor Model Language
(SML) OGC`s XML-based language for describing and encoding sensors (in situ, satellite and airborne).
sensor web
A networked collection of sensors that can be remotely read and perhaps also controlled.
Sensor Web Enablement
OGC`s initiative to develop standards that support linking of environmental sensors to the World Wide Web. A Sensor Collection Service (SCS) server gathers readings from in-situ environmental sensors via a private network (cellular, microwave, etc.), and provides summaries or interpretations of those readings to SCS clients over the Web.
A computation performed by a software entity on one side of an interface in response to a request made by a software entity on the other side of the interface. A collection of operations, accessible through an interface, that allows a user to evoke a behavior of value to the user. ISO - 19119
service chain
A sequence of services where, for each adjacent pair of services, occurrence of the first action is necessary for the occurrence of the second action ISO 19119.
service interface
Source: ISO 19101
Shared boundary between an automated system or human being and another automated system or human being
service metadata
The most basic operation all OGC services must provide is the ability to describe themselves. This "Get Capabilities" operation, yielding a capabilities document, is common to all OWS1 services. An XML vocabulary comprised of several parts for describing different aspects of a service. The first unit describes the service interface in sufficient detail so that an automated process can read the description and invoke an operation that the service advertises. A second unit describes the data content of the service (or the data it operates on) in a way that enables service requestors to dynamically compose requests for service.
Service Model
The general model for online services.
service request
A request by a client of an operation from a service.
An ESRI published spatial data format.
Standard interchange format. SIF is a format which allows data to be transferred among dissimilar computer systems. SQL stands for Structured Query Language, a relational database.
Simple Feature Model
The general, descriptive model for how earth features may be represented as vector objects (i.e., points, lines and polygons).
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Small or Medium Sized Enterprise (1-500 employed persons)
Source: http://www.softwareag.com/xml/about/glossary.htm
"Simple Object Access Protocol, a method invented by Microsoft to use RPC over the internet via HTTP calls. SOAP is now published as an W3C Note and implemented, among others, as part of the Apache XML Project." SOAP is a protocol specification that defines a uniform way of passing XML-encoded data. It also defines a way to perform remote procedure calls (RPCs) using HTTP as the underlying communication protocol. Development of SOAP is in the care of the W3C`s XML Protocols Working Group.
spatial reference system
Source: The OpenGIS® Abstract Specification Topic 2: "Spatial Referencing by Coordinates" http://www.opengis.org/techno/abstract/02-102.pdf
As defined in the OpenGIS Abstract Specification Topic 2 and ISO 19111. Position on or near the Earth's surface can be described by spatial reference systems. These are of two basic types: those using coordinates; and those based on geographic identifiers (for example postal addresses, administrative areas). Spatial referencing by geographic identifiers is defined in ISO 19112, Geographic information - "Spatial referencing by geographic identifiers." The subject matter of The OpenGIS® Abstract Specification Topic 2: "Spatial Referencing by Coordinates" is spatial referencing by coordinates.
Spatial Web
The Spatial Web is the spatially enabled World Wide Web. It is also the set of Web-resident open geospatial resources -- data, schemas and services - that enable people to publish, find and use Web-resident geospatial information off all kinds.
A document written by a consortium, vendor, or user that specifies a technological area with a well-defined scope, primarily for use by developers as a guide to implementation. A specification is not necessarily a formal standard.
Specification Program
The OGC Specification Program provides an industry consensus process to plan, review and officially adopt OpenGIS Specifications for interfaces and protocols that enable interoperable geoprocessing services, data, and applications. The OGC bodies involved in the Specification Program are the Technical Committee, Planning Committee, and Strategic Member Advisory Committee.
Source: http://www.softwareag.com/xml/about/glossary.htm
Structured Query Language. "SQL is a standard interactive and programming language for getting information from and updating a database. Although SQL is both an ANSI and an ISO standard, many database products support SQL with proprietary extensions to the standard language"
A document that specifies a technological area with a well-defined scope, usually by a formal standardization body and process.
State Plane Coordinate System (SPC)
A locational reference system developed in the U.S. in the 1930s which provides positional descriptions accurate to 1 foot in 10,000. The SPC system divides the United States into 125 zones (5 cover Texas) and employs both Lambert conformal and Transverse Mercator projections (depending upon a state`s size and shape). Within any given SPC zone, X-Y coordinates are given in eastings and northings. A central meridian passes each zone and is given a false easting of 2 million feet. A false northing of 0 feet is established below the southern limit of each zone.
stove pipe or stove piped
Colloquial term describing systems that are 'islands of automation,' that do not interoperate with other systems. Data in at the bottom, data out at the top, no sharing of data or services laterally.
Strategic Member Advisory Committee (SMAC)
The SMAC is granted authority to operate by the OGC by-laws. The SMAC has as a primary responsibility to recommend areas of strategic opportunity for Consortium operations and to recommend resource strategies in support of Consortium programs to the Board of Directors, Consortium staff and the Membership.
structured code
Refers to software designed such that a small central program makes calls to subroutines organized in external libraries: as opposed to the `spaghetti` code of large monolithic programs with integral functions and subroutines. This approach enables libraries called application programming interfaces (APIs) to provide a standard set of `hooks` by which a program can cooperate with other programs.
Styles provide the mapping from feature types and feature properties and constraints to parameterized symbols used in drawing maps
Styled Layer Descriptors (SLD)
A map-styling language for producing georeferenced maps with user-defined styling
Source: http://www.softwareag.com/xml/about/glossary.htm
"A program written in a stylesheet language for converting and/or presenting HTML, SGML, or XML documents. Stylesheet languages are e.g. CSS for HTML (and CSS2 for XML too), XSL for XML and FOSI and DSSSL for both SGML and XML."
Collection of components. E.g. Customer Management contains many software components including Party, Location, Post Code look-up, and assign new ID number.
2-deminsional geometric primitive, locally representing a continuous image of a region of a plane. (see OGC Abstract Specification (Topic 1) clause 6.3.17)
Surface Configuration Model
Defines the geometric characteristics of the Earth`s surface, exclusive of features which fall upon the surface; defined in terms of elevation, shape, roughness, slope, and aspect, with the later properties possibly derived from elevation.
"Scalable Vector Graphics, a language for describing two-dimensional vector and mixed vector/raster graphics in XML. SVG graphic types include text and XSLT can transform XML documents into SVG output. Thus SVG is a possible replacement for XSL FO. SVG tools are provided by IBM, CSIRO and Adobe." SVG is a standard application programming interface (API) for displaying graphics encoded in XML. SVG is used for presentation of GML data.
Symbols are bundles of predefined graphical parameters and predefined fixed graphic "images".
Methodology for describing symbols and mapping of the schema to an application schema. Portrayal requires symbology.
Calling application requires response to request before proceeding.
System Internal Interface (SII)
An interface between components within an application platform.

Glossary of Terms - L

Local Area Network. A system for connecting computers so they can communicate with one another.
A particular system of US satellites that scan the earth at a variety of wavelengths. The satellites return information that can be used to inventory and analyze a variety of natural and human resources.
language independent
Describes a standard or specification which is not specified in terms of a specific programming language, but is implementable in a variety of languages.
layered map visualization
Pictoral representation of geographic data
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
See Location Based Services
legacy system
In computing terms, a legacy System includes software or database components inherited from a previous computing model which do not fit into an open system environment without some modification. In the case of the OpenGIS Specification, legacy systems are modified to include OpenGIS-conformant interfaces.
line string
A set of coordinate points and the lines that join them.
Location Based Services (LBS)
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
Location Based Services (or "Location Services") deliver information about location to people who are using wireless, position-aware devices such as cell phones and PDAs. A wireless-IP service that uses geographic information to serve a mobile user. Any application service that exploits the position of a mobile terminal.
Location Dependent Services
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
"Services in which the location of the client, server or both form an integral part of the service "
Location Organizer Folder (LOF)
The general, multi-source information container model for handling sets of inter-related spatiotemporal information, including images, maps, features, cables, and any other information elements (e.g., audio, video, etc).
location service
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
A service that provides the location of a moving or fixed device
Long-Term Technical Baseline Target
The Long-Term Technical Baseline Target is the subset of the elements of the Technical Plan that are scheduled to be completed greater than two calendar years into the future.
loosely-coupled service
A service that can be used to operate on multiple, unspecified datasets. Calling application has no structural dependency on the interface of called application. Call is not made in same technology as the interface of the called application.
Lempel-Zif-Welch: a popular data compression technique developed in 1977 by J. Ziv and A Lempel. Unisys researcher Terry Welch later created an enhanced version of these methods, and Unisys holds a patent on the algorithm. It is widely used in many hardware and software products, including V.42bis modems, GIF and TIFF files and PostScript Level 2.

Glossary of Terms - E

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

Glossary of Terms - W

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

Glossary of Terms - P

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