An example of a feature coverage opened in an ILWIS map panel
A feature coverage in ILWIS refer to maps containing closed areas (polygons), lines (segments) and points. A feature coverage has to have a domain, a coordinate system and a representation. Features in a feature coverage are either codified by IDs, class names or values; depending on the domain of the coverage. A feature coverage can be obtained via digitizing an analog map or vectorizing a raster coverage.
Closed areas (polygons) in a feature coverage, represent e.g., uniquely codified areas such as cadastral plots, or mapping units such as land use classes, geological formations or soil types. Lines (segments) in a feature coverage represents e.g., boundaries of polygons, roads, rivers, railways, or isolines, while points represent water wells, meteorological stations, location of field measurements, etc.