Module org.opengis.geoapi

Package org.opengis.referencing.crs

Interface SingleCRS

All Superinterfaces:

CoordinateReferenceSystem, IdentifiedObject, ReferenceSystem

All Known Subinterfaces:

DerivedCRS, EngineeringCRS, GeneralDerivedCRS, GeocentricCRS, GeodeticCRS, GeographicCRS, ImageCRS, ParametricCRS, ProjectedCRS, TemporalCRS, VerticalCRS

@Classifier(ABSTRACT)
@UML(identifier="SingleCRS",
     specification=ISO_19111)
public interface SingleCRS
extends CoordinateReferenceSystem

Base type of CRS related to an object by a datum or datum ensemble. The object will generally, but not necessarily, be the Earth. It can be identified either by a datum or a datum ensemble. At least one of those two properties shall be present.

The valid coordinate system type and the datum type are constrained by the CRS type. For example, GeographicCRS can be associated only to GeodeticReferenceFrame (a specialization of Datum) and EllipsoidalCS. The constraints are documented in the Javadoc of sub-interfaces.

Since:

2.0

See Also:

• CoordinateSystem
• Datum

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
CoordinateSystem	getCoordinateSystem()	Returns the coordinate system associated to this CRS.
Datum	getDatum()	Returns the datum associated directly or indirectly to this CRS.
default DatumEnsemble<?>	getDatumEnsemble()	Returns the datum ensemble associated directly or indirectly to this CRS.

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)
CoordinateSystem getCoordinateSystem()

Returns the coordinate system associated to this CRS. The coordinate system (CS) is composed of a set of coordinate axes with specified units of measure. The CS subtype implies the mathematical rules that define how coordinate values are calculated from distances, angles and other geometric elements and vice versa.

Specified by:

getCoordinateSystem in interface CoordinateReferenceSystem

Returns:

the coordinate system associated to this CRS.

getDatum

@UML(identifier="datum",
     obligation=CONDITIONAL,
     specification=ISO_19111)
Datum getDatum()

Returns the datum associated directly or indirectly to this CRS. In the case of DerivedCRS, this method returns the datum of the base CRS. This property may be null if this CRS is related to an object identified only by a datum ensemble.

A datum specifies the relationship of a coordinate system to the object, thus ensuring that the abstract mathematical concept “coordinate system” can be applied to the practical problem of describing positions of features on or near the planet's surface by means of coordinates. The object will generally, but not necessarily, be the Earth. For certain CRSs, the object may be a moving platform.

Returns:

the datum, or null if this CRS is related to an object identified only by a datum ensemble.

Convenience extension to OGC/ISO standard

The ISO specification declares the datum as absent when the association is indirect. GeoAPI recommends to follow the link to the base CRS for users convenience.

Condition:

Mandatory if the datum ensemble is not documented.

getDatumEnsemble

@UML(identifier="datumEnsemble",
     obligation=CONDITIONAL,
     specification=ISO_19111)
default DatumEnsemble<?> getDatumEnsemble()

Returns the datum ensemble associated directly or indirectly to this CRS. In the case of DerivedCRS, this method returns the datum ensemble of the base CRS. This property may be null if this CRS is related to an object identified only by a single datum.

The default implementation returns null.

Returns:

the datum ensemble, or null if this CRS is related to an object identified only by a single datum.

Since:

3.1

Condition:

Mandatory if the datum is not documented.