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A coverage is the digital representation of some spatio-temporal phenomenon. Coverages play an important role in geographic information systems, geospatial content and services, GIS data processing, and data sharing. A coverage is a special kind of geographic feature, with the distinguishing characteristics that other features have one particular value associated (such as a road number, which remains constant over all the road's extent) whereas a coverage typically conveys different values at different locations. A coverage is represented by its "domain" (the universe of extent) and a number of range of values representing the coverage's value at each defined location. For example, a satellite image derived from remote sensing might record varying degrees of light pollution. Aerial photography, land cover data, and digital elevation models all provide coverage data. Generally, a coverage can be multi-dimensional, such as 1-D sensor timeseries, 2-D satellite images, 3-D x/y/t image time series or x/y/z geo tomograms, or 4-D x/y/z/t climate and ocean data. An interoperable service definition for navigating, accessing, processing, and aggregation of coverages is provided by the Open Geospatial Consortium (OGC) Web Coverage Service (WCS). == Standards == Coverages represent digital geospatial information representing space/time-varying phenomena. OGC Abstract Topic 6〔(Topic 6 - Schema for coverage geometry and functions, OGC 07-011 )〕 - which is identical to ISO 19123 - defines an abstract model of coverages. As such, it is not a suitable basis for implementations: many implementations are conceivable which all conform to this abstract model, but are not interoperable. This coverage model is concretized to the level of interoperability by the OGC standard GML 3.2.1 Application Schema - Coverages〔(OGC GML Application Schema - Coverages, OGC 09-146r2 )〕 (often referred to as GMLCOV) which in turn is based on the Geography Markup Language (GML) 3.2,〔(OpenGIS Geography Markup Language (GML) Encoding Standard, OGC 07-036 )〕 an XML grammar written in XML Schema for the description of application schemas as well as the transport and storage of geographic information. The European legal framework for a unified Spatial Data Infrastructure, INSPIRE, in its Annex II and III relies on the OGC definitions of coverages as well, but modifies them in places in a way making them less compatible and interoperable with the OGC standard. For example, components of the coverage concept are selectively recombined into new, different definitions of a coverage. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Coverage data」の詳細全文を読む スポンサード リンク
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