OGC Glossary

Glossary of Terms - M

Definitions: 
map
A two-dimensional visual portrayal of geospatial data. A map is not the data itself.
map projection
A coordinate conversion from a geodetic coordinate system to a planar surface, converting geodetic latitude and longitude to plane (map) coordinates. The result is a two-dimensional coordinate system called a projected coordinate reference system.
map scale
The relationship between distance on a map and the corresponding distance on the earth`s surface. Map scale is often recorded as a representative fraction such as 1:1,000,000 (1 unit on the map represents a million units on the earth`s surface) or 1:24,000 (1 unit on the map represents 24,000 units on the earth`s surface). The terms `large` and `small` refer to the relative magnitude of the representative fraction. Since 1/1,000,000 is a smaller fraction than 1/24,000, the former is said to be a smaller scale. Small scales are often used to map large areas because each map unit covers a larger earth distance. Large-scale maps are employed for detailed maps of smaller areas.
measurement
An observation event whose value property is a value of some natural phenomenon. A measurement usually refers to the measuring device and procedure used to determine the value, such as a sensor or observer, analytical procedure, simulation or other numerical process. A measurement feature binds the result to the (spatiotemporal) location where the measurement was made.
message broker
Hubs designed to route and manage message traffic between various applications. May include transformation for incompatible messages.
metadata
Source: ISO 19115; KOGIS Switzerland; Co-ordination for GIS in the federal administration of Switzerland
"Data about data or a service. Metadata is the documentation of data. In human-readable form, it has primarily been used as information to enable the manager or user to understand, compare and interchange the content of the described data set. In the Web Services context, XML-encoded (machine-readable and human-readable) metadata stored in catalogs and registries enables services to use those catalogs and registries to find data and services.
metadata dataset
Source: ISO 19101
Metadata describing a specific dataset
metadata entity
Source: ISO 19115
Group of metadata elements and other metadata entities describing the same aspect of data. Note 1: A metadata entity may contain one or more metadata entities. Note 2: A metadata entity is equivalent to a class in UML terminology
metadata schema
Source: ISO 19101
Coceptual schema describing metadata Note: ISO 19115 describes a standard for metadata schema.
metadata section
Source: ISO 19115
Subset of metadata that defines a collection of related metadata entities and elements.
metadata translator
Software based on the OpenGIS Specification that will be configured by two diverse Information Communities to enable automated data integration or sharing to the degree that their metadata schema overlap.
Mid-Term Technical Baseline Target
The Mid-Term Technical Baseline Target is the subset of the elements of the Technical Plan that are scheduled to be completed between one and two calendar years into the future.
middleware
Software in a distributed computing environment that mediates between clients and servers.
MMI
OGC`s Multi-Hazard Mapping Initiative (MMI) Phase I (2001) was a pilot project sponsored by the US Federal Emergency Management Agency (FEMA) that established a limited operational framework of interoperable services to illustrate the advantages of using products with OGC interfaces to access, fuse and visualize critical spatial information in support of FEMA multi-hazard mitigation, response and recovery functions.
modeling languages
Well-known "languages" to encode the semantics, syntax and schema of geospatial and geoprocessing-related information resources. They apply to all Application Domain Models and Runtime (Model) Components.
MPP
OGC`s Military Pilot Project (MPP) (2001) was a collaborative effort that tested the interoperability of commercial geoprocessing products in the defense and intelligence (DI) domain.
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Glossary of Terms - F

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

Glossary of Terms - X

Definitions: 
XIMA
XML for Imagery and Map Annotations, OGC Discussion Paper 01-018: 29.XML Linking Language (XLink), Version 1.0, DeRose, S., Maler, E., Orchard, D., available at: http://www.w3.org/TR/xlink/
XML
Source: PreANVIL Glossary http://www.anvil.eu.com/find/Glossary-english.htm
XML (eXtensible Markup Language) is the predominant form for interoperable, self-describing data/content, in combination with XML schema definition language. See http://www.w3.org/XML/. XML has its roots in SGML, the Standard Generalized Markup Language (an ISO standard). The development of XML came about because of perceived limitations in HTML when used as a tool for publishing complex documents on the Web. http://www.w3.org.
XML for Imagery and Map Annotations (XIMA)
The means to encode annotations on imagery, maps, and other geospatial data.
XML for Location Services (XLS)
The encoding method for OpenLS-based Abstract Data Types.
XSLT
"(eXtensible Stylesheet Language Transformation) A language used to convert an XML document into another XML document or into HTML, PDF or some other format."
Glossary: 

Glossary of Terms - J

Definitions: 
JAVA
A platform independent programming language developed by SunSoft. Any computer with the Java server software installed can run Java client applets that arrive over a network.
JPG (JPEG)
JPEG (Joint Photographic Experts Group) Image format for continuous tone pictures: JPEG makes use of continuous-tone digital images much more economical by drastically reducing the volume required for storage and the bandwidth required for transmission.
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: 

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