Coordinate system axis Topic 2 - Spatial referencing by coordinates
Copyright © 2010 Open Geospatial Consortium, Inc.
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EXAMPLE 1 The combination {Latitude, Lat, north, degree} would lead to one instance of the object class
“coordinate system axis”; the combination {Latitude, j, north, degree} to another instance, the axis abbreviation being different.
In this Abstract Specification, usage of coordinate system axis names shall be constrained by geodetic custom, depending on the coordinate reference system type. These
constraints are shown in Table 16. This constraint shall work in two directions.
EXAMPLE 2 As “geodetic latitude“ and “geodetic longitude” are used as names for coordinate axes forming a
geodetic coordinate reference system, these terms cannot also be used in another context.
Aliases for these constrained names shall be permitted.
Table 16 — Naming constraints for coordinate system axis
CS type When used in
CRS type Permitted coordinate system axis names
Cartesian geodetic
geocentric X, geocentric Y, geocentric Z Cartesian
projected northing or southing, easting or westing
ellipsoidal geodetic
geodetic latitude, geodetic longitude, [ellipsoidal height if 3D]
spherical geodetic
spherical latitude, spherical longitude, geocentric radius vertical
vertical depth or gravity-related height
Image and engineering coordinate reference systems may make use of names specific to the local context or custom.
Coordinate system axes are described further in B.2.2.