OGC Glossary

Glossary of Terms - T

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

Glossary of Terms - M

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.
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.
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.
Software in a distributed computing environment that mediates between clients and servers.
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.
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.

Glossary of Terms - F

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.
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.
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.)
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 of Terms - X

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/
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.
"(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 of Terms - J

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.
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.