Module org.apache.sis.referencing

Package org.apache.sis.referencing.datum

package org.apache.sis.referencing.datum

Relationship of a Coordinate­System (an abstract mathematical entity) to the earth or other system. 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 in this package is Abstract­Datum. Various subclasses are defined for various kinds of relationship to the Earth or time (geodetic, vertical, temporal), or to platforms (mobile or not) (engineering, image). Some of those SIS subclasses provide additional methods that are not part of OGC/ISO specifications:

• Default­Ellipsoid.get­Authalic­Radius()
• Default­Ellipsoid.get­Eccentricity()
• Default­Prime­Meridian.get­Greenwich­Longitude(Unit)
• Default­Geodetic­Datum.get­Bursa­Wolf­Parameters()
• Default­Geodetic­Datum.get­Position­Vector­Transformation(Geodetic­Datum, Extent)

Datum shifts

Three classes are provided in support of coordinate transformations between different datums:

• Bursa­Wolf­Parameters performs an approximation based on a translation, rotation and scale of geocentric coordinates.
• Time­Dependent­BWP is like Bursa­Wolf­Parameters, but varies with time for taking in account the motion of plate tectonic.
• Datum­Shift­Grid is used for more accurate transformations than what Bursa­Wolf­Parameters allows, by interpolating the geographic or geocentric translations in a grid (e.g. NADCON or NTv2) instead of apply the same transformation for every points.

Since:

0.4

Related Packages

Module	Package	Description
org.apache.sis.referencing	org.apache.sis.referencing	Base classes for reference systems used for general positioning.
org.apache.sis.referencing	org.apache.sis.referencing.crs	Coordinate Reference System (CRS) definitions as coordinate systems related to the earth through datum.
org.apache.sis.referencing	org.apache.sis.referencing.cs	Coordinate System (CS) definitions as the set of coordinate system axes that spans the coordinate space.
org.apache.sis.referencing	org.apache.sis.referencing.factory	Creates Coordinate Reference System (CRS) objects from given properties or authority codes.
org.apache.sis.referencing.gazetteer	org.apache.sis.referencing.gazetteer	Mapping between geographic identifiers (addresses, grid indexes…) and locations (descriptions, coordinates…).
org.apache.sis.referencing	org.apache.sis.referencing.operation	Relationship between any two Coordinate Reference Systems (CRS).

Classes

Class	Description
AbstractDatum	Specifies the relationship of a Coordinate System to the earth.
BursaWolfParameters	Parameters for a geographic transformation between two datum having the same prime meridian.
DatumShiftGrid<C extends Quantity<C>,T extends Quantity<T>>	Small but non-constant translations to apply on coordinates for datum shifts or other transformation process.
DefaultEllipsoid	Geometric figure that can be used to describe the approximate shape of the earth.
DefaultEngineeringDatum	Defines the origin of an engineering coordinate reference system.
DefaultGeodeticDatum	Defines the location and orientation of an ellipsoid that approximates the shape of the earth.
DefaultImageDatum	Defines the origin of an image coordinate reference system.
DefaultParametricDatum	Defines the origin of a parametric coordinate reference system.
DefaultPrimeMeridian	Defines the origin from which longitude values are determined.
DefaultTemporalDatum	Defines the origin of a temporal coordinate reference system.
DefaultVerticalDatum	Identifies a particular reference level surface used as a zero-height surface.
TimeDependentBWP	Parameters for a time-dependent geographic transformation between two datum.