Module org.opengis.geoapi

Package org.opengis.referencing.datum

Interface Datum

All Superinterfaces:

IdentifiedObject

All Known Subinterfaces:

DynamicReferenceFrame, EngineeringDatum, GeodeticDatum, ImageDatum, ParametricDatum, TemporalDatum, VerticalDatum

@Classifier(ABSTRACT)
@UML(identifier="Datum",
     specification=ISO_19111)
public interface Datum
extends IdentifiedObject

Specifies the relationship of a coordinate system to an object. For geodetic and vertical coordinate reference systems (CRS), the datum relates the coordinate system to the Earth or other celestial body. With other types of CRSs, the datum may relate the coordinate system to another physical or virtual object.

A datum uses a parameter or set of parameters that determine the location of the origin of the CRS. Each datum subtype can be associated with only specific types of coordinate systems, documented in their javadoc.

Since:

1.0

See Also:

• CoordinateSystem
• CoordinateReferenceSystem

Field Summary

Fields

Modifier and Type	Field	Description
static final String	ANCHOR_DEFINITION_KEY	Key for the "anchorDefinition" property to be given to the DatumFactory.createFoo(Map, ...) methods.
static final String	ANCHOR_EPOCH_KEY	Key for the "anchorEpoch" property to be given to the DatumFactory.createFoo(Map, ...) methods.
static final String	ANCHOR_POINT_KEY	Deprecated. Renamed ANCHOR_DEFINITION_KEY for conformance with ISO 19111:2019 revision.
static final String	CONVENTIONAL_RS_KEY	Key for the "conventionalRS" property to be given to the DatumFactory.createFoo(Map, ...) methods.
static final String	DOMAIN_OF_VALIDITY_KEY	Deprecated. Moved to ObjectDomain as of ISO 19111:2019.
static final String	PUBLICATION_DATE_KEY	Key for the "publicationDate" property to be given to the DatumFactory.createFoo(Map, ...) methods.
static final String	REALIZATION_EPOCH_KEY	Deprecated. Renamed ANCHOR_EPOCH_KEY for conformance with ISO 19111:2019 revision.
static final String	SCOPE_KEY	Deprecated. Moved to ObjectDomain as of ISO 19111:2019.

Fields inherited from interface org.opengis.referencing.IdentifiedObject

ALIAS_KEY, DOMAINS_KEY, IDENTIFIERS_KEY, NAME_KEY, REMARKS_KEY

Method Summary

Modifier and Type	Method	Description
default Optional<InternationalString>	getAnchorDefinition()	Returns a description of the relationship used to anchor the coordinate system to the Earth or alternate object.
default Optional<Temporal>	getAnchorEpoch()	Returns the epoch at which a static datum matches a dynamic datum from which it has been derived.
default InternationalString	getAnchorPoint()	Deprecated. Renamed getAnchorDefinition() for conformance with ISO 19111:2019 revision.
default Optional<IdentifiedObject>	getConventionalRS()	Returns the name, identifier, alias and remarks for the reference system realized by this reference frame.
default Extent	getDomainOfValidity()	Deprecated. Replaced by IdentifiedObject.getDomains() as of ISO 19111:2019.
default Optional<Temporal>	getPublicationDate()	Returns the date on which the datum definition was published.
default Date	getRealizationEpoch()	Deprecated. Renamed getAnchorEpoch() for conformance with ISO 19111:2019 revision.
default InternationalString	getScope()	Deprecated. Replaced by IdentifiedObject.getDomains() as of ISO 19111:2019.

Methods inherited from interface org.opengis.referencing.IdentifiedObject

getAlias, getDomains, getIdentifiers, getName, getRemarks, toWKT

Field Details

ANCHOR_DEFINITION_KEY

static final String ANCHOR_DEFINITION_KEY

Key for the "anchorDefinition" property to be given to the DatumFactory.createFoo(Map, ...) methods. This is used for setting the value to be returned by getAnchorDefinition().

Since:

3.1

See Also:

• DatumFactory
• getAnchorDefinition()
• Constant Field Values

ANCHOR_POINT_KEY

@Deprecated(since="3.1")
static final String ANCHOR_POINT_KEY

Deprecated.

Renamed ANCHOR_DEFINITION_KEY for conformance with ISO 19111:2019 revision.

Key for the "anchorPoint" property to be given to the DatumFactory.createFoo(Map, ...) methods. This is used for setting the value to be returned by getAnchorDefinition().

See Also:

• DatumFactory
• getAnchorDefinition()
• Constant Field Values

ANCHOR_EPOCH_KEY

static final String ANCHOR_EPOCH_KEY

Key for the "anchorEpoch" property to be given to the DatumFactory.createFoo(Map, ...) methods. This is used for setting the value to be returned by getAnchorEpoch().

Since:

3.1

See Also:

• DatumFactory
• getAnchorEpoch()
• Constant Field Values

REALIZATION_EPOCH_KEY

@Deprecated(since="3.1")
static final String REALIZATION_EPOCH_KEY

Deprecated.

Renamed ANCHOR_EPOCH_KEY for conformance with ISO 19111:2019 revision.

Key for the "realizationEpoch" property to be given to the DatumFactory.createFoo(Map, ...) methods. This is used for setting the value to be returned by getRealizationEpoch().

See Also:

• DatumFactory
• getRealizationEpoch()
• Constant Field Values

DOMAIN_OF_VALIDITY_KEY

@Deprecated(since="3.1")
static final String DOMAIN_OF_VALIDITY_KEY

Deprecated.

Moved to ObjectDomain as of ISO 19111:2019.

Key for the "domainOfValidity" property to be given to the DatumFactory.createFoo(Map, ...) methods.

See Also:

• DatumFactory
• ObjectDomain.getDomainOfValidity()
• Constant Field Values

SCOPE_KEY

@Deprecated(since="3.1")
static final String SCOPE_KEY

Deprecated.

Moved to ObjectDomain as of ISO 19111:2019.

Key for the "scope" property to be given to the DatumFactory.createFoo(Map, ...) methods.

See Also:

• DatumFactory
• ObjectDomain.getScope()
• Constant Field Values

PUBLICATION_DATE_KEY

static final String PUBLICATION_DATE_KEY

Key for the "publicationDate" property to be given to the DatumFactory.createFoo(Map, ...) methods. This is used for setting the value to be returned by getPublicationDate().

Since:

3.1

See Also:

• DatumFactory
• getPublicationDate()
• Constant Field Values

CONVENTIONAL_RS_KEY

static final String CONVENTIONAL_RS_KEY

Key for the "conventionalRS" property to be given to the DatumFactory.createFoo(Map, ...) methods. This is used for setting the value to be returned by getConventionalRS().

Since:

3.1

See Also:

• DatumFactory
• getConventionalRS()
• Constant Field Values

Method Details

getAnchorDefinition

@UML(identifier="anchorDefinition",
     obligation=OPTIONAL,
     specification=ISO_19111)
default Optional<InternationalString> getAnchorDefinition()

Returns a description of the relationship used to anchor the coordinate system to the Earth or alternate object. The definition may include coordinates of an identified point or points. Also known as the "origin", especially for EngineeringDatums.

• For GeodeticDatum, the anchor may be a set of station coordinates. if the reference frame is dynamic, it will also include coordinate velocities. For a traditional geodetic datum, the anchor may be a point known as the fundamental point, which is traditionally the point where the relationship between geoid and ellipsoid is defined, together with a direction from that point.
• For a VerticalDatum, the anchor may be the zero level at one or more defined locations or a conventionally defined surface.
• For an EngineeringDatum, the anchor may be an identified physical point with the orientation defined relative to the object.

Returns:

a description of the anchor point.

Since:

3.1

getAnchorPoint

@Deprecated(since="3.1")
@UML(identifier="anchorPoint",
     obligation=OPTIONAL,
     specification=ISO_19111,
     version=2003)
default InternationalString getAnchorPoint()

Deprecated.

Renamed getAnchorDefinition() for conformance with ISO 19111:2019 revision.

A description of the relationship used to anchor the coordinate system to the Earth or alternate object.

Returns:

a description of the anchor point, or null if none.

getAnchorEpoch

@UML(identifier="anchorEpoch",
     obligation=OPTIONAL,
     specification=ISO_19111)
default Optional<Temporal> getAnchorEpoch()

Returns the epoch at which a static datum matches a dynamic datum from which it has been derived. This time may be precise or merely a year (e.g. 1983 for NAD83). In the latter case, the epoch usually refers to the year in which a major recalculation of the geodetic control network, underlying the datum, was executed or initiated.

This epoch should not be confused with the frame reference epoch of dynamic reference frames. Nor with the epoch at which a reference frame is defined to be aligned with another reference frame. this information should be included in the datum anchor definition.

Returns:

epoch at which a static datum matches a dynamic datum from which it has been derived.

Since:

3.1

See Also:

• Year
• YearMonth
• LocalDate

getRealizationEpoch

@Deprecated(since="3.1")
@UML(identifier="realizationEpoch",
     obligation=OPTIONAL,
     specification=ISO_19111,
     version=2007)
default Date getRealizationEpoch()

Deprecated.

Renamed getAnchorEpoch() for conformance with ISO 19111:2019 revision.

The time after which this datum definition is valid.

Returns:

the datum realization epoch, or null if not available.

getDomainOfValidity

@Deprecated(since="3.1")
@UML(identifier="domainOfValidity",
     obligation=OPTIONAL,
     specification=ISO_19111,
     version=2007)
default Extent getDomainOfValidity()

Deprecated.

Replaced by IdentifiedObject.getDomains() as of ISO 19111:2019.

Area or region or timeframe in which this datum is valid.

Returns:

the datum valid domain, or null if not available.

getScope

@Deprecated(since="3.1")
@UML(identifier="scope",
     obligation=OPTIONAL,
     specification=ISO_19111,
     version=2007)
default InternationalString getScope()

Deprecated.

Replaced by IdentifiedObject.getDomains() as of ISO 19111:2019.

Description of domain of usage, or limitations of usage, for which this datum object is valid.

Returns:

a description of domain of usage, or null if none.

Departure from OGC/ISO standard for historical reason

This method has been kept conformant with the specification published in 2003. The revision published in 2007 replaced the singleton by a collection and changed the obligation from "optional" to "mandatory", requiring a return value of not known if the scope is unknown.

getPublicationDate

@UML(identifier="publicationDate",
     obligation=OPTIONAL,
     specification=ISO_19111)
default Optional<Temporal> getPublicationDate()

Returns the date on which the datum definition was published. Should be an instance of LocalDate, but other types are also allowed. For example, a publication date may be merely a Year.

Returns:

date on which the datum definition was published.

Since:

3.1

getConventionalRS

@UML(identifier="conventionalRS",
     obligation=OPTIONAL,
     specification=ISO_19111)
default Optional<IdentifiedObject> getConventionalRS()

Returns the name, identifier, alias and remarks for the reference system realized by this reference frame. Examples: "ITRS" for ITRF88 through ITRF2008 and ITRF2014, or "EVRS" for EVRF2000 and EVRF2007. All datums that are members of a datum ensemble shall have the same conventional reference system.

Returns:

reference system realized by this reference frame.

Since:

3.1