Module org.opengis.geoapi

Package org.opengis.referencing.crs

Interface GeographicCRS

All Superinterfaces:

CoordinateReferenceSystem, GeodeticCRS, IdentifiedObject, ReferenceSystem, SingleCRS

@UML(identifier="GeographicCRS",
     specification=ISO_19111)
public interface GeographicCRS
extends GeodeticCRS

A 2- or 3-dimensional CRS 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 planet's surface. A 2D geographic CRS is used when positions of features are described on the surface of the reference ellipsoid. A 3D geographic CRS is used when positions are described on, above or below the reference ellipsoid.

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 ProjectedCRSs.

The GeodeticDatum associated to this CRS must have an Ellipsoid. I.e., the ellipsoid is generally optional but become mandatory in the context of GeographicCRS.

Permitted coordinate systems

This type of CRS can be used with coordinate systems of type EllipsoidalCS only.

Since:

1.0

See Also:

• CRSAuthorityFactory.createGeographicCRS(String)
• CRSFactory.createGeographicCRS(Map, GeodeticDatum, DatumEnsemble, EllipsoidalCS)

Field Summary

Fields inherited from interface org.opengis.referencing.IdentifiedObject

ALIAS_KEY, DOMAINS_KEY, IDENTIFIERS_KEY, NAME_KEY, REMARKS_KEY

Fields inherited from interface org.opengis.referencing.ReferenceSystem

DOMAIN_OF_VALIDITY_KEY, SCOPE_KEY

Method Summary

Modifier and Type	Method	Description
EllipsoidalCS	getCoordinateSystem()	Returns the coordinate system, which shall be ellipsoidal.

Methods inherited from interface org.opengis.referencing.crs.GeodeticCRS

getDatum, getDatumEnsemble

Methods inherited from interface org.opengis.referencing.IdentifiedObject

getAlias, getDomains, getIdentifiers, getName, getRemarks, toWKT

Methods inherited from interface org.opengis.referencing.ReferenceSystem

getDomainOfValidity, getScope

Method Details

getCoordinateSystem

@UML(identifier="coordinateSystem",
     obligation=MANDATORY,
     specification=ISO_19111)
EllipsoidalCS getCoordinateSystem()

Returns the coordinate system, which shall be ellipsoidal.

Specified by:

getCoordinateSystem in interface CoordinateReferenceSystem

Specified by:

getCoordinateSystem in interface SingleCRS

Returns:

the ellipsoidal coordinate system.