A discrete coverage consists of a domain set, range set and optionally a coverage function. The domain set consists of either spatial or temporal geometry objects, finite in number. The range set is comprised of a finite number of attribute values each of which is associated to every direct position within any single spatiotemporal object in the domain. In other words, the range values are constant on each spatiotemporal object in the domain. This coverage function maps each element from the coverage domain to an element in its range. The coverageFunction element describes the mapping function.This element serves as the head of a substitution group which may contain any discrete coverage whose type is derived from gml:DiscreteCoverageType.
The attribute gml:id supports provision of a handle for the XML element representing a GML Object. Its use is mandatory for all GML objects. It is of XML type ID, so is constrained to be unique in the XML document within which it occurs.
Source
<element name="AbstractDiscreteCoverage" type="gml:DiscreteCoverageType" abstract="true" substitutionGroup="gml:AbstractCoverage"><annotation><documentation>A discrete coverage consists of a domain set, range set and optionally a coverage function. The domain set consists of either spatial or temporal geometry objects, finite in number. The range set is comprised of a finite number of attribute values each of which is associated to every direct position within any single spatiotemporal object in the domain. In other words, the range values are constant on each spatiotemporal object in the domain. This coverage function maps each element from the coverage domain to an element in its range. The coverageFunction element describes the mapping function. This element serves as the head of a substitution group which may contain any discrete coverage whose type is derived from gml:DiscreteCoverageType.</documentation></annotation></element>