Revisit term Elevation

[dschristianson]

Submitter: Danielle Christianson

I suggest the following changes:
Revisit the term "Elevation".
It is currently defined as "Elevation at point with respect to earth's surface given as a heigh or depth relative to ground surface" and has no units.

Typically, the vertical distance relative to the local ground surface (or other feature) is called height or depth.
Elevation is usually the vertical distance to a global reference system.
The current definition confuses these 2 common practices.

Also, the use of ground surface can be confusing / not appropriate when water bodies are in play and/or remote sensing technologies.

Units should be defined at a minimum. If elevation is truly desired, a datum should be specified in the definition or added as a separate field for users to specify.

In land-based measurements, sometimes elevation is reported as the globally-referenced ground surface height and a local measurement height / depth is reported referenced to that ground surface.