Module org.opengis.geoapi

Package org.opengis.referencing.crs

Interface DerivedCRS

All Superinterfaces:

CoordinateReferenceSystem, GeneralDerivedCRS, IdentifiedObject, ReferenceSystem, SingleCRS

All Known Subinterfaces:

ProjectedCRS

@UML(identifier="DerivedCRS",
     specification=ISO_19111)
public interface DerivedCRS
extends GeneralDerivedCRS

A CRS that is defined by applying a coordinate conversion to another preexisting CRS. The derived CRS inherits its datum (reference frame) or datum ensemble from its base CRS. A DerivedCRS instance may also implement one of the interfaces listed below, provided that the conditions in the right column are met:

Derived CRS types

Type	Conditions
ProjectedCRS	Base CRS is a GeographicCRS and conversion is a map projection.
GeodeticCRS	Base CRS is also a GeodeticCRS.
VerticalCRS	Base CRS is also a VerticalCRS.
TemporalCRS	Base CRS is also a TemporalCRS.
EngineeringCRS	Base CRS is a GeodeticCRS, ProjectedCRS or EngineeringCRS.

Projected CRS

In the special case where the CRS is derived from a base GeographicCRS by applying a coordinate conversion known as a map projection to latitude and longitude ellipsoidal coordinate values, the ProjectedCRS subtype should be used. Projected CRSs are modeled as a special case of derived CRS because of their importance in geographic information.

Derived projected CRS

In the special case where the CRS is derived from a base ProjectedCRS, the coordinate system of the derived CRS is not necessarily Cartesian. But the derived CRS still inherit the distortion characteristics of the base projected CRS.

Since:

1.0

See Also:

• CRSAuthorityFactory.createDerivedCRS(String)
• CRSFactory.createDerivedCRS(Map, CoordinateReferenceSystem, Conversion, CoordinateSystem)

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
CoordinateReferenceSystem	getBaseCRS()	Returns the CRS that is the base for this derived CRS.
Conversion	getConversionFromBase()	Returns the conversion from the base CRS to this derived CRS.
default Datum	getDatum()	Returns the same datum as the base CRS.
default DatumEnsemble<?>	getDatumEnsemble()	Returns the same datum ensemble as the base 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

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

getCoordinateSystem

Method Details

getBaseCRS

@UML(identifier="baseCRS",
     obligation=MANDATORY,
     specification=ISO_19111)
CoordinateReferenceSystem getBaseCRS()

Returns the CRS that is the base for this derived CRS. This is the source CRS of the deriving conversion.

Upcoming API change — specialization
According ISO 19111, the return type should be SingleCRS. This change may be applied in GeoAPI 4.0.

Specified by:

getBaseCRS in interface GeneralDerivedCRS

Returns:

the CRS that is the base for this derived CRS.

getConversionFromBase

@UML(identifier="derivingConversion",
     obligation=MANDATORY,
     specification=ISO_19111)
Conversion getConversionFromBase()

Returns the conversion from the base CRS to this derived CRS. The source CRS of the conversion, if non null, shall be the base CRS. The target CRS of the conversion, if non-null, shall be this CRS.

Specified by:

getConversionFromBase in interface GeneralDerivedCRS

Returns:

the conversion from the base CRS to this derived CRS.

Departure from OGC/ISO standard in the name

Was toBase in OGC 01-009, conversion in ISO 19111:2007 and derivingConversion in ISO 19111:2019. By analogy with 01-009, GeoAPI defines a method name which contains the "FromBase" words for making clear which CRS is the source or which one is the target.

getDatum

default Datum getDatum()

Returns the same datum as the base CRS. This property may be null if the base CRS is related to an object identified only by a datum ensemble.

Specified by:

getDatum in interface SingleCRS

Returns:

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

getDatumEnsemble

default DatumEnsemble<?> getDatumEnsemble()

Returns the same datum ensemble as the base CRS. This property may be null if the base CRS is related to an object identified only by a single datum.

Specified by:

getDatumEnsemble in interface SingleCRS

Returns:

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

Since:

3.1