15. Coordinate reference systems

Coordinate reference system identifiers are used in many places in deegree webservices:

• In incoming service requests (e.g. GetFeature-requests to the WFS)
• In a lot of resource configuration files (e.g. in Feature stores)

deegree has an internal CRS database that contains many commonly used coordinate reference systems. Some examples for valid CRS identifiers:

• EPSG:4258
• http://www.opengis.net/gml/srs/epsg.xml#4258
• urn:ogc:def:crs:epsg::4258
• urn:opengis:def:crs:epsg::4258

Tip

As a rule of thumb, deegree’s CRS database uses the EPSG:12345 identifier variant to indicate XY axis order, while the URN variants (such as urn:ogc:def:crs:epsg::12345) always use the official axis order defined by the EPSG. For example EPSG:4258 and urn:ogc:def:crs:epsg::4258 both refer to ETRS89, but EPSG:4258 means ETRS89 in XY-order, while urn:ogc:def:crs:epsg::4258 is YX (the official order defined by the EPSG for this CRS).

Note

The CRS subsystem is not fully integrated with the deegree workspace yet. Rework and proper documentation are on the roadmap for one of the next releases. If you have trouble finding a specific CRS, please contact the deegree mailing lists for support.