[Tagging] Feature proposal - RFC - ele with units

[Minh Nguyen]

(Crossposted to talk-us)

And now for something unrelated to route relations. I've written up a 
proposal that would:

* Tweak the definition of the ele=* key to accept values in feet, as 
long as the unit is specified, just like height=*, maxheight=*, etc. A 
bare number without a unit symbol would continue to be in meters.

* Deprecate the ele:ft=* key, which was never approved but would be 
redundant to the modified ele=*.

This proposal would primarily affect the United States, where it has 
always been fairly common to tag elevations in feet when mapping by 
hand, as opposed to importing. However, ele=* is an approved key that is 
consumed by many global renderers, so it would be unfair to quietly 
change the documentation without a wider discussion.

Please note that this proposal only concerns units of measurement in the 
database, not orthogonal considerations like sources of elevation data, 
geodetic datums, and so forth. I realize it's a complicated subject. The 
photo examples are only provided to illustrate the ubiquity of 
elevations in feet in the U.S.

I welcome your feedback about this proposal. You may want to leave 
comments on the wiki talk page instead of posting here, because Mailman 
will probably munge any crossposting between this list and talk-us.

https://wiki.openstreetmap.org/wiki/Proposed_features/ele_with_units

(P.S.: This is my first proposal, so please don't bite. Figured I'd 
start small!)

-- 
minh at nguyen.cincinnati.oh.us