Interface CoordinateSystemAxis

All Superinterfaces:

@UML(identifier="CoordinateSystemAxis", specification=ISO_19111) public interface CoordinateSystemAxis extends IdentifiedObject
Definition of a coordinate system axis. Each axis is characterized by a unique combination of name, abbreviation, direction and unit.

Axis name

Usage of coordinate system axis names is constrained by geodetic custom in a number of cases, depending mainly on the coordinate reference system type. These constraints are shown in the table below. This constraint works in two directions; for example the names geodetic latitude and geodetic longitude shall be used to designate the coordinate axis names associated with a geographic coordinate reference system. Conversely, these names shall not be used in any other context.
Context of coordinate system axis names usage
CS CRS Permitted coordinate system axis names
CartesianGeodetic “geocentric X”, “geocentric Y”, “geocentric Z
CartesianProjected “easting” or “westing”, “northing” or “southing”, “ellipsoidal height” (if 3D)
EllipsoidalGeographic “geodetic latitude”, “geodetic longitude”, “ellipsoidal height” (if 3D)
SphericalGeodetic “spherical latitude”, “spherical longitude”, “geocentric radius” (if 3D)
“geocentric latitude”, “geodetic longitude”, “geocentric radius” (if 3D)
“geocentric co-latitude”, “geodetic longitude”, “geocentric radius” (if 3D)
VerticalVertical “depth” or “gravity-related height”
Parametric, temporal and engineering coordinate reference systems may make use of names specific to the local context or custom and are therefore not included as constraints in the above list.

Axis direction

The direction of the coordinate axes is often only approximate. Two geographic coordinate reference systems will make use of the same ellipsoidal coordinate system. These coordinate systems are associated with the planet through two different geodetic reference frames, which may lead to the two systems being slightly rotated with respect to each other.
See Also: