org.opengis.referencing.datum
Interface PrimeMeridian

Show UML class diagram

All Superinterfaces:

IdentifiedObject

@UML(identifier="CD_PrimeMeridian",
     specification=ISO_19111)
public interface PrimeMeridian
extends IdentifiedObject

A prime meridian defines the origin from which longitude values are determined. The default name is "Greenwich", and that value shall be used when the greenwich longitude value is zero.

Since:

1.0

See Also:

DatumAuthorityFactory.createPrimeMeridian(String), DatumFactory.createPrimeMeridian(Map, double, Unit)

Field Summary

Fields inherited from interface IdentifiedObject

ALIAS_KEY, IDENTIFIERS_KEY, NAME_KEY, REMARKS_KEY

Method Summary

Unit<Angle>	getAngularUnit() Returns the angular unit of the Greenwich longitude.
double	getGreenwichLongitude() Longitude of the prime meridian measured from the Greenwich meridian, positive eastward.

Methods inherited from interface IdentifiedObject

getAlias, getIdentifiers, getName, getRemarks, toWKT

Method Detail

getGreenwichLongitude

@UML(identifier="greenwichLongitude",
     obligation=CONDITIONAL,
     specification=ISO_19111)
double getGreenwichLongitude()

Longitude of the prime meridian measured from the Greenwich meridian, positive eastward. The greenwichLongitude initial value is zero, and that value shall be used when the meridian name value is "Greenwich".

Returns:

The prime meridian Greenwich longitude, in angular unit.

getAngularUnit

@UML(identifier="getAngularUnit",
     specification=OGC_01009)
Unit<Angle> getAngularUnit()

Returns the angular unit of the Greenwich longitude.

Note: This attribute is inherited from an older OGC specification. ISO 19111 compliant applications or GML documents shall always express prime meridians in decimal degrees.

Returns:

The angular unit of Greenwich longitude.