Coverage data
Encyclopedia
In geographic information system
s, a coverage is a map
ping of one aspect of data
in space
. It represents a "domain" (the universe of extent) in terms of characteristics expressing a range of values. For example: a satellite
image derived from remote sensing
might record varying degrees of light pollution
. Aerial photography
, land cover data, and digital elevation model
s all provide coverage data.
In contrast to coverage data we find feature data
, which concentrates more on the numerous characteristics of a spot and less on its spatial surrounds.
. The Coverage model was a revolutionary concept, extending CAD
formats into more spatially-aware data that featured linked attribute
s. Coverages processed using the BUILD and CLEAN commands are 2D planar datasets that maintain topological
information, thus a polygon "knows" which segments of its perimeter it shares with adjacent polygons. Due to the lack of processing power in computing at the time of its development, the Coverage model employs indexed binary file
s to store spatial and attribute data separately as opposed to utilizing a RDBMS.
, a protocol for delivering coverage data.
Geographic Information System
A geographic information system, geographical information science, or geospatial information studies is a system designed to capture, store, manipulate, analyze, manage, and present all types of geographically referenced data...
s, a coverage is a map
Map
A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....
ping of one aspect of data
Data
The term data refers to qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which...
in space
Space
Space is the boundless, three-dimensional extent in which objects and events occur and have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum...
. It represents a "domain" (the universe of extent) in terms of characteristics expressing a range of values. For example: a satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
image derived from remote sensing
Remote sensing
Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth by means of propagated signals Remote sensing...
might record varying degrees of light pollution
Light pollution
Light pollution, also known as photopollution or luminous pollution, is excessive or obtrusive artificial light.The International Dark-Sky Association defines light pollution as:...
. Aerial photography
Aerial photography
Aerial photography is the taking of photographs of the ground from an elevated position. The term usually refers to images in which the camera is not supported by a ground-based structure. Cameras may be hand held or mounted, and photographs may be taken by a photographer, triggered remotely or...
, land cover data, and digital elevation model
Digital elevation model
A digital elevation model is a digital model or 3-D representation of a terrain's surface — commonly for a planet , moon, or asteroid — created from terrain elevation data....
s all provide coverage data.
In contrast to coverage data we find feature data
Feature data
In geographic information systems, a feature is an object that can have a geographic location and other properties. Common types of geometries include points, arcs, and polygons. Carriageways and cadastres are examples of feature data...
, which concentrates more on the numerous characteristics of a spot and less on its spatial surrounds.
GIS format
"Coverage" is the term typically applied to the legacy Arc/INFO format developed by ESRIESRI
Esri is a software development and services company providing Geographic Information System software and geodatabase management applications. The headquarters of Esri is in Redlands, California....
. The Coverage model was a revolutionary concept, extending CAD
Computer-aided design
Computer-aided design , also known as computer-aided design and drafting , is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer...
formats into more spatially-aware data that featured linked attribute
Attribute (computing)
In computing, an attribute is a specification that defines a property of an object, element, or file. It may also refer to or set the specific value for a given instance of such....
s. Coverages processed using the BUILD and CLEAN commands are 2D planar datasets that maintain topological
Geospatial topology
Geospatial topology studies the rules concerning the relationships between the points, lines, and polygons that represent the features of a geographic region. For example, where two polygons represent adjacent counties, typical topological rules would require that the counties share a common...
information, thus a polygon "knows" which segments of its perimeter it shares with adjacent polygons. Due to the lack of processing power in computing at the time of its development, the Coverage model employs indexed binary file
Binary file
A binary file is a computer file which may contain any type of data, encoded in binary form for computer storage and processing purposes; for example, computer document files containing formatted text...
s to store spatial and attribute data separately as opposed to utilizing a RDBMS.
Web Coverage Service
"Coverage" may also refer to WCSWeb Coverage Service
The Open Geospatial Consortium Web Coverage Service Interface Standard provides an interface allowing requests for geographical coverages across the web using platform-independent calls...
, a protocol for delivering coverage data.