- All Superinterfaces:
@UML(identifier="SC_GeographicCRS", specification=ISO_19111, version=2003) public interface GeographicCRS extends GeodeticCRSA 2- or 3-dimensional coordinate reference system based on an ellipsoidal approximation of the geoid. This provides an accurate representation of the geometry of geographic features for a large portion of the earth's surface.
A Geographic CRS is not suitable for mapmaking on a planar surface, because it describes geometry on a curved surface. It is impossible to represent such geometry in a Euclidean plane without introducing distortions. The need to control these distortions has given rise to the development of the science of map projections.
This type of CRS can be used with coordinate systems of type
Departure from OGC/ISO specification:
- See Also:
CRSFactory.createGeographicCRS(Map, GeodeticDatum, EllipsoidalCS)
- The distinction between those two types is in wide use.
- A distinct geographic type allows GeoAPI to restrict the coordinate system type to
EllipsoidalCS. ISO 19111 uses a
unionfor expressing this restriction at the
SC_GeodeticCRSlevel, but the Java language does not provide such construct. A distinct geographic type is one way to achieve the same goal.
This interface is kept conformant with the specification published in 2003. The 2007 revision of ISO 19111 removed the
SC_GeocentricCRStypes, handling both using the
SC_GeodeticCRSparent type. GeoAPI keeps them for two reasons:
All Methods Instance Methods Abstract Methods Modifier and Type Method Description
getCoordinateSystem()Returns the coordinate system, which shall be ellipsoidal.
Methods inherited from interface IdentifiedObject
getAlias, getIdentifiers, getName, getRemarks, toWKT
@UML(identifier="coordinateSystem", obligation=MANDATORY, specification=ISO_19111) EllipsoidalCS getCoordinateSystem()Returns the coordinate system, which shall be ellipsoidal.