Module org.apache.sis.referencing
Package org.apache.sis.referencing.crs
package org.apache.sis.referencing.crs
Coordinate Reference System (CRS) definitions as coordinate systems related to the earth through datum.
An explanation for this package is provided in the OpenGIS® javadoc.
The remaining discussion on this page is specific to the SIS implementation.
The root class for this package is AbstractCRS
.
Coordinate Reference System (CRS) can have various number of dimensions, but some restrictions
apply depending on the CRS type:
Dimension  CRS type examples  Remarks 

3  Geographic, Geocentric  ISO 19111 uses the same class, GeodeticCRS , for those two cases. 
2  Geographic, Projected  GeographicCRS can also be 3D. 
1  Vertical, Temporal.  
Any  Compound  Often used for adding a time axis to the above CRS. 
Apache SIS extensions
Some SIS implementations provide additional methods that are not part of OGC/ISO specifications:AbstractCRS.forConvention(AxesConvention)
DefaultTemporalCRS.toDate(double)
DefaultTemporalCRS.toValue(Date)
GeodeticCRS
type. OGC/ISO distinguishes the geographic/geocentric cases according the type
of the coordinate system associated to that CRS:
 A geodetic CRS associated to an ellipsoidal CS is geographic.
 A geodetic CRS associated to a spherical or Cartesian CS is geocentric.
 Since:
 0.4

ClassDescriptionCoordinate reference system, defined by a coordinate system and (usually) a datum.A CRS describing the position of points through two or more independent coordinate reference systems.A coordinate reference system that is defined by its coordinate conversion from another CRS (not by a datum).A 1, 2 or 3dimensional contextually local coordinate reference system.A 3dimensional coordinate reference system with the origin at the approximate centre of mass of the earth.A 2 or 3dimensional coordinate reference system based on an ellipsoidal approximation of the geoid.A 2dimensional engineering coordinate reference system applied to locations in images.A 1dimensional coordinate reference system which uses parameter values or functions.A 2dimensional coordinate reference system used to approximate the shape of the earth on a planar surface.A 1dimensional coordinate reference system used for the recording of time.A 1dimensional coordinate reference system used for recording heights or depths.