Key:ele:wgs84

From OpenStreetMap Wiki
Jump to navigation Jump to search
Public-images-osm logo.svg ele:wgs84
Geoidheight de.svg
Description
ellipsoid height of a point in WGS84 (h in the image) Edit or translate this description.
Group: Properties
Used on these elements
may be used on nodesmay be used on waysmay be used on areasshould not be used on relations
Status: in use

Wikidata

This is a tag for explicitly tagging a ellipsoidal height in the wgs84 system (World Geodetic System, Revision 1984). A well known problem of the values in the generic ele=* tag is that despite the definition, the reference isn’t homogeneous.

If used on areas and linear ways, the elevation must be true for the whole object. Otherwise use the tag on nodes.

Common errors

It used to be very vague whether this tag specifies a geoid height (using one of the EGM geoid models tied to WGS84's many revisions) or an ellipsodial height, until the altitude page has kind of clarified (but with great conflict with the other pages). The two values can be very different, on the order of tens of meters.

Generally, if the value you find on this tag is very similar to any mean-sea-level height, there's a good chance someone is doing it wrong. Look up the EGM96 geoid height over the area to make sure it's really not because the geoid happens to be near the ellipsoid, then move it to ele=*.

See also