Package org.deegree.cs.projections

A map projection create a 2D view of the 3D-Object 'earth', by doing so, some information is inevitably lost.

See:
Description

Interface Summary

IProjection

Interface describing a general projection

Class Summary

Projection

Map conversion is the process of changing the map grid coordinates (usually, but not always, Easting & Northing) of a Projected Coordinate Reference System to its corresponding geographical coordinates (Latitude & Longitude) or vice versa.

Enum Summary

SupportedProjectionParameters	The SupportedProjectionParameters enumeration defines currently supported projection parameters
SupportedProjections	The SupportedProjections enumeration defines currently supported projections

Package org.deegree.cs.projections Description

A map projection create a 2D view of the 3D-Object 'earth', by doing so, some information is inevitably lost.

Because of this and because of the fact, the earth isn't a perfect sphere --or even a perfect ellipsoid for that matter--, there is no 'best' projection for the projection of every region on earth. Hence a lot of different mathematical projectional functions have been developed over the years. It is possible to categorize these functions into three groups:

• Cylindric projections
• Conic projections
• Azimuthal projections

Automatic loading of projection classes

It is possible to create your own projection classes, which can be automatically loaded by the org.deegree.cs.configuration.deegree.xml.DeegreeCRSProvider class.

You can achieve this loading by supplying the class attribute to a crs:projectedCRS/crs:projection element in the 'deegree-crs-configuration.xml'. This attribute must contain the full class name (with package), e.g. <crs:projection class='my.package.and.projection.Implementation'>

Because the loading is done with reflections your classes must sustain following criteria:

Projections

1. It must be a sub class of Projection
2. A constructor with following signature must be supplied:
   public MyProjection(
    GeographicCRS underlyingCRS,
    double falseNorthing,
    double falseEasting,
    javax.vecmath.Point2d naturalOrigin,
    Unit units,
    double scale,
    java.util.List<org.w3c.dom.Element> yourProjectionElements
);


   The first six parameters are common to all projections (for an explanation of their meaning take a look at Projection). The last list, will contain all xml-dom elements you supplied in the deegree configuration (child elements of the crs:projection/crs:MyProjection), thus relieving you of the parsing of the deegree-crs-configuration.xml document.

Version:

$Revision: 30120 $, $Date: 2007-03-20 10:15:15 +0100 (Di, 20 Mrz 2007)$

Author:

Rutger Bezema, last edited by: $Author: aschmitz $