Coverage data

Not to be confused with the ARC/INFO Coverage file format from Esri.

A coverage is the digital representation of some spatio-temporal phenomenon. ISO 19123 provides the definition:

  • [a] feature that acts as a function to return values from its range for any direct position within its spatial, temporal or spatiotemporal domain

Coverages play an important role in geographic information systems (GIS), geospatial content and services, GIS data processing, and data sharing.

A coverage is represented by its "domain" (the universe of extent) and a collection representing the coverage's values at each defined location within its range. 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.

However, coverages are more general than just regularly gridded imagery. The corresponding standards (see below) address regular and irregular grids, point clouds, and general meshes.

An interoperable service definition for navigating, accessing, processing, and aggregation of coverages is provided by the Open Geospatial Consortium (OGC) Web Coverage Service (WCS) suite and Web Coverage Processing Service (WCPS), a spatio-temporal coverage query language.