Class DefaultGeographicCRS

All Implemented Interfaces:
Serializable, Formattable, Deprecable, Lenient­Comparable, Printable, Coordinate­Reference­System, Geodetic­CRS, Geographic­CRS, Single­CRS, Identified­Object, Reference­System

public class DefaultGeographicCRS extends AbstractCRS implements GeographicCRS
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.

Used with datum type: Geodetic.
Used with coordinate system type: Ellipsoidal.

Creating new geographic CRS instances

New instances can be created either directly by specifying all information to a factory method (choices 3 and 4 below), or indirectly by specifying the identifier of an entry in a database (choices 1 and 2 below). Choice 1 in the following list is the easiest but most restrictive way to get a geographic CRS. The other choices provide more freedom.
  1. Create a Geographic­CRS from one of the static convenience shortcuts listed in Common­CRS​.geographic() or Common­CRS​.geographic3D().
  2. Create a Geographic­CRS from an identifier in a database by invoking Geodetic­Authority­Factory​.create­Geographic­CRS(String).
  3. Create a Geographic­CRS by invoking the CRSFactory​.create­Geographic­CRS(…) method (implemented for example by Geodetic­Object­Factory).
  4. Create a Geographic­CRS by invoking the constructor.
Example: the following code gets a two-dimensional geographic CRS using the World Geodetic System 1984 datum:
GeodeticDatum datum = CommonCRS.WGS84.geographic();

Immutability and thread safety

This class is immutable and thus thread-safe if the property values (not necessarily the map itself), the coordinate system and the datum instances given to the constructor are also immutable. Unless otherwise noted in the javadoc, this condition holds if all components were created using only SIS factories and static constants.
Since:
0.4
See Also:
  • Constructor Details

  • Method Details

    • castOrCopy

      public static DefaultGeographicCRS castOrCopy(GeographicCRS object)
      Returns a SIS coordinate reference system implementation with the same values as the given arbitrary implementation. If the given object is null, then this method returns null. Otherwise if the given object is already a SIS implementation, then the given object is returned unchanged. Otherwise a new SIS implementation is created and initialized to the attribute values of the given object.
      Parameters:
      object - the object to get as a SIS implementation, or null if none.
      Returns:
      a SIS implementation containing the values of the given object (may be the given object itself), or null if the argument was null.
    • getInterface

      public Class<? extends GeographicCRS> getInterface()
      Returns the GeoAPI interface implemented by this class. The SIS implementation returns Geographic­CRS​.class.

      Note for implementers

      Subclasses usually do not need to override this method since GeoAPI does not define Geographic­CRS sub-interface. Overriding possibility is left mostly for implementers who wish to extend GeoAPI with their own set of interfaces.
      Returns:
      Geographic­CRS​.class or a user-defined sub-interface.
    • getPrimeMeridian

      public PrimeMeridian getPrimeMeridian()
      Returns the prime meridian which is indirectly (through a datum) associated to this CRS. If the datum is non-null, then this method returns the datum prime meridian. Otherwise, if all members of the datum ensemble use the same prime meridian, then this method returns that meridian.
      Returns:
      the prime meridian indirectly associated to this CRS.
      Throws:
      No­Such­Element­Exception - if there is no datum and the ensemble does not contain at least one member.
      Geodetic­Exception - if the prime meridian is not the same for all members of the datum ensemble.
      Since:
      1.5
    • getEllipsoid

      public Ellipsoid getEllipsoid()
      Returns the ellipsoid which is indirectly (through a datum) associated to this CRS. If the datum is non-null, then this method returns the datum ellipsoid. Otherwise, if all members of the datum ensemble use the same ellipsoid, then this method returns that ellipsoid.
      Returns:
      the ellipsoid indirectly associated to this CRS.
      Throws:
      No­Such­Element­Exception - if there is no datum and the ensemble does not contain at least one member.
      Geodetic­Exception - if the ellipsoid is not the same for all members of the datum ensemble.
      Since:
      1.5
    • getDatum

      public final GeodeticDatum getDatum()
      Returns the geodetic reference frame associated to this geographic CRS. This property may be null if this CRS is related to an object identified only by a datum ensemble.
      Specified by:
      get­Datum in interface Geodetic­CRS
      Specified by:
      get­Datum in interface Single­CRS
      Returns:
      the geodetic reference frame, or null if this CRS is related to an object identified only by a datum ensemble.
    • getDatumEnsemble

      public DefaultDatumEnsemble<GeodeticDatum> getDatumEnsemble()
      Returns a collection of datums which, for low accuracy requirements, may be considered to be insignificantly different from each other. This property may be null if this CRS is related to an object identified only by a single datum.
      Warning: in a future SIS version, the return type may be changed to the org​.opengis​.referencing​.datum​.Datum­Ensemble interface. This change is pending GeoAPI revision.
      Returns:
      the datum ensemble, or null if this CRS is related to an object identified only by a single datum.
      Since:
      1.5
    • getCoordinateSystem

      public EllipsoidalCS getCoordinateSystem()
      Returns the coordinate system.
      Specified by:
      get­Coordinate­System in interface Coordinate­Reference­System
      Specified by:
      get­Coordinate­System in interface Geographic­CRS
      Specified by:
      get­Coordinate­System in interface Single­CRS
      Overrides:
      get­Coordinate­System in class Abstract­CRS
      Returns:
      the coordinate system.
    • forConvention

      public DefaultGeographicCRS forConvention(AxesConvention convention)
      Returns a CRS equivalent to this one but with axes rearranged according the given convention. If this CRS is already compatible with the given convention, then this method returns this.
      Overrides:
      for­Convention in class Abstract­CRS
      Parameters:
      convention - the axes convention for which a coordinate reference system is desired.
      Returns:
      a coordinate reference system compatible with the given convention (may be this).
      See Also:
    • formatTo

      protected String formatTo(Formatter formatter)
      Formats this CRS as a Well Known Text Geographic­CRS[…] element.

      Example

      Well-Known Text (version 2) of a geographic coordinate reference system using the WGS 84 datum.
      GeographicCRS["WGS 84",
         Datum["World Geodetic System 1984",
           Ellipsoid["WGS84", 6378137.0, 298.257223563, LengthUnit["metre", 1]]],
           PrimeMeridian["Greenwich", 0.0, AngleUnit["degree", 0.017453292519943295]],
         CS["ellipsoidal", 2],
           Axis["Latitude", north],
           Axis["Longitude", east],
           AngleUnit["degree", 0.017453292519943295],
         Area["World"],
         BBox[-90.00, -180.00, 90.00, 180.00],
         Scope["Used by GPS satellite navigation system."],
         Id["EPSG", 4326, Citation["IOGP"], URI["urn:ogc:def:crs:EPSG::4326"]]]
      

      Same coordinate reference system using WKT 1.

      GEOGCS["WGS 84",
         DATUM["World Geodetic System 1984",
           SPHEROID["WGS84", 6378137.0, 298.257223563]],
           PRIMEM["Greenwich", 0.0],
         UNIT["degree", 0.017453292519943295],
         AXIS["Latitude", NORTH],
         AXIS["Longitude", EAST],
         AUTHORITY["EPSG", "4326"]]
      
      Parameters:
      formatter - the formatter where to format the inner content of this WKT element.
      Returns:
      "Geodetic­CRS" (WKT 2) or "Geog­CS" (WKT 1).
      See Also: