Package org.opengis.referencing.crs
Interface GeographicCRS
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- All Superinterfaces:
CoordinateReferenceSystem
,GeodeticCRS
,IdentifiedObject
,ReferenceSystem
,SingleCRS
@UML(identifier="SC_GeographicCRS", specification=ISO_19111, version=2003) public interface GeographicCRS extends GeodeticCRS
A 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
EllipsoidalCS
.- Since:
- 1.0
- See Also:
CRSAuthorityFactory.createGeographicCRS(String)
,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 aunion
for expressing this restriction at theSC_GeodeticCRS
level, but the Java language does not provide such construct. A distinct geographic type is one way to achieve the same goal.
Departure from OGC/ISO specification:
This interface is kept conformant with the specification published in 2003. The 2007 revision of ISO 19111 removed theSC_GeographicCRS
andSC_GeocentricCRS
types, handling both using theSC_GeodeticCRS
parent type. GeoAPI keeps them for two reasons:
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Field Summary
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Fields inherited from interface IdentifiedObject
ALIAS_KEY, IDENTIFIERS_KEY, NAME_KEY, REMARKS_KEY
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Fields inherited from interface ReferenceSystem
DOMAIN_OF_VALIDITY_KEY, SCOPE_KEY
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Method Summary
Modifier and Type Method Description EllipsoidalCS
getCoordinateSystem()
Returns the coordinate system, which shall be ellipsoidal.-
Methods inherited from interface GeodeticCRS
getDatum
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Methods inherited from interface IdentifiedObject
getAlias, getIdentifiers, getName, getRemarks, toWKT
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Methods inherited from interface ReferenceSystem
getDomainOfValidity, getScope
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Method Detail
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getCoordinateSystem
@UML(identifier="coordinateSystem", obligation=MANDATORY, specification=ISO_19111) EllipsoidalCS getCoordinateSystem()
Returns the coordinate system, which shall be ellipsoidal.- Specified by:
getCoordinateSystem
in interfaceCoordinateReferenceSystem
- Specified by:
getCoordinateSystem
in interfaceSingleCRS
- Returns:
- the ellipsoidal coordinate system.
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