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Glossary
BANDWIDTH
A measure of the amount of data that can reliably be transmitted through a channel per unit of time, typically measured in bits or bytes per second.
BIOME
An ecological formation including both plants and animals. Traditionally biomes are identified in terms of their characteristic vegetation form.
CADASTRE
A map that is accompanied by a register showing the ownership or possession of individual units of land to facilitate efficient land administration and expedite land market transactions.
CALLING POINTS
Points from which telephone calls can be made. (A slightly different use of this term is common in computer programming.)
CAPACITY
The ability to undertake certain activities, solve problems, and achieve objectives, such as interpreting a map (an example of human capacity), managing computer networks (organizational capacity), or sharing data (societal capacity). Capacity is built by enhancing these abilities.
CONNECTIVITY
The degree to which a communications service is available to the public, typically measured in telephones or Internet connections per unit of population.
DECISION-MAKERS
In the context of sustainable development, those who choose actions that directly or indirectly affect the environment and reside in all levels of government, the citizenry, the private sector, non-governmental organizations, or overseas development agencies, for example.
DECISION-SUPPORT SYSTEM (DSS)
The integration of geographically referenced data in a problem-solving situation.
DEVELOPMENT
For the purposes of this report, see sustainable development.
DEVELOPED COUNTRIES
Countries with “high” gross national income as defined by the World Bank.
DEVELOPING COUNTRIES
Countries with “low” or “medium” gross national income as defined by the World Bank.
DIGITAL DIVIDE
This term describes the gap in access between developed and developing countries or within a country to information and communication technologies.
DIGITAL ELEVATION MODEL (DEM)
A digital rep-resentation of the elevation of locations on Earth’s surface. A DEM is often used in reference to a set of elevation values representing the elevations at points in a rectangular grid.
EL NIÑO
An episodic global weather phenomenon driven by conditions in the western Pacific Ocean.
E-READINESS
This term is used to suggest the readiness of an organization, community, or country to use the Internet generally or to use it for business, commercial, or governmental purposes. A number of organizations have proposed instruments to measure e-readiness, and these instruments differ somewhat.
GEODETIC CONTROL
Reference points on Earth whose exact positions are determined to a high degree of accuracy through measurement.
GEOGRAPHICALLY REFERENCED DATA
Data with known latitude, longitude, and elevation, or other horizontal and vertical coordinates.
GEOGRAPHIC INFORMATION SYSTEM (GIS)
A digital information system that is designed to work with data referenced by spatial or geographic coordinates.
GEOGRAPHIC POSITION
Refers to horizontal coordinates as well as elevation of objects and features.
GEOGRAPHY
An integrative discipline that brings together the physical and human dimensions of the world in the study of people, places, and environments. Its subject matter is Earth’s surface and the processes that shape it, the relationships between people and environments, and the connections between people and places.
GLOBAL POSITIONING SYSTEM (GPS)
A network of satellites controlled by the U.S. Department of Defense that is designed to help aerial and ground-based units with an appropriate receiver determine their current location.
GSM
An acronym for Global System of Mobile Communication, one of several competing standards for mobile telephones.
INFORMATION
Data that humans assimilate and evaluate to solve a problem or to make a decision.
LEGACY DATA
Maps, aerial photographs, reports, and other documents that often function as baseline information.
LOCAL AREA NETWORK
Personal computers linked into a network in a limited geographic area, such as a building or campus, as distinguished from a wide area network or stand-alone computers.
METADATA
A term used to describe information about data. Metadata usually includes information on data quality, currency, lineage, ownership, and feature classification.
OPEN SOURCE SOFTWARE
Software for which the original or source code is freely available to the user or other interested parties. Most commercial software firms make the original source code available only under specific circumstances, usually to collaborating firms, providing the user with only a machine readable version of the software that is difficult to read and/or modify. In some cases, most notably Linux, an open source operating system, large communities have formed around the development and maintenance of specific open source software packages. Open source software is of special interest to developing countries in that its development and maintenance cost is born by communities of volunteers, and it is available without charge, or with minimal charges for the provision of disks, manuals, and support.
ORTHO-IMAGE
A specially processed image prepared from an aerial photograph or remotely sensed image that has the metric qualities of a traditional line map with the rich detail of an aerial image.
PENETRATION
The degree to which a technology has penetrated a community or country. Indicators of penetration include the number of points of presence (i.e., points at which calls are routed for transmission by a long-distance, interexchange carrier), the percentage of organizations of a given type (e.g. businesses, schools, health centers) that have access to a service or the number of secondary cities that have Internet service providers in a country.
PHOTOGRAMMETRY
The art, science, and technology of obtaining reliable information about physical objects and the environment through the processes of recording, measuring, and interpreting photographic images and patterns of electromagnetic radiant energy and other phenomena.
PLACE-BASED STUDIES
The systematic analysis of social, economic, political, and environmental processes operating in a place that provides an integrated understanding of its distinctiveness or character.
RADAR INTERFEROMETRY
A technique in which two radar images are taken from slightly different locations and differences between these images allow for the calculation of surface elevation.
REMOTE-SENSING
The measurement or acquisition of information of some property of an object or phenomenon, by a recording device that is not in physical or intimate contact with the object or phenomenon under study.
RESOLUTION
A way of detecting variation. In remote-sensing, there is spatial resolution (the variation caused by distance separating adjacent pixels), spectral resolution (the variation caused by the spectral responses within a wavelength band), and temporal resolution (the variation caused by time over the same location).
RIFT VALLEY FEVER (RVF)
An acute, fever-causing viral disease that affects domestic animals (such as cattle, buffalo, sheep, goats, and camels) and humans. RVF is most commonly associated with mosquito-borne epidemics during years of heavy rainfall. RVF is generally found in regions of eastern and southern Africa where sheep and cattle are raised. RVF virus also exists in most countries of sub-Saharan Africa and Madagascar.
SCHISTOSOMIASIS
One of the major communicable diseases of public health and socio-economic importance in the developing world. Direct mortality is relatively low, but the disease burden is high in terms of chronic pathology and disability. The distribution is particularly related to large-scale water development. Despite control efforts in a num-
ber of countries, still an estimated 200 million people are infected, of which 120 million are symptomatic and 20 million have severe disease. An estimated 80 percent of all cases and all of the most severely affected are concentrated in Africa.
SELECTIVE AVAILABILITY
The restriction of access to or the adjustment of the precision of geographic positioning information by introducing a bias to the system.
SPATIAL DATA INFRASTRUCTURE (SDI)
The institutional framework, policies, technologies, and data requirements to enable spatial data to be used to support economic growth and social and environmental interests.
SUSTAINABLE DEVELOPMENT
Development that meets the needs of the present without compromising the ability of future generations to meet their own needs (from Our Common Future, Oxford University Press, 1987).
TELECENTER
A center offering telephone and other communications services to the public. There are many different kinds of telecenters and many business models under which telecenters are operated in Africa.
TELEDENSITY
The number of telephone connections per unit of population, typically measured by the number of fixed lines per unit of population, number of mobile phones per unit of population, or both.
TELEPHONY
The art or practice of operating telephones or telephone services.
VSAT (Very Small Aperture Terminal)
Direct link to communications satellites, typically using antennas less than 2 meters in diameter. In Africa an increasing number of organizations have Internet linkages through VSAT terminals, bypassing the local telephone service.
