Does anyone have any idea whether the elevations, be they in feet or
metres, are all respecting the wiki definition of being the height above
MSL according to EGM96 (not sure what that would mean in landlocked
areas) and NOT WGS84 or (strictly speaking) relative to local MSL?
The wiki page for ele[1] says this:
ELEVATION (HEIGHT ABOVE SEA LEVEL) OF A POINT IN METRES. This is mainly
intended for mountain peaks [2] but could also be used for elevation of
airport runways and many other objects. For OpenStreetMap, this value
should be in meters above above mean sea level as defined by the EGM96
[3] geoid model. This elevation is usually very close to national "above
sea level" systems with differences < 1m. This is not the height above
the WGS84 ellipsoid (see Geoid [4]) which is shown as raw elevation by
some satellite navigation devices and which can differ from geoid
elevation by up to 100m.
If we can't even rely on the reference point for these elevations,
discussions about feet vs. metres (assuming the unit is indicated
properly) are close to "bikeshedding".
//colin
[1] http://wiki.openstreetmap.org/wiki/Key:ele
On 2017-09-08 10:39, Andrew Hain wrote:
> Or, indeed, you could put a conversion in the editor between the mapper
> typing a figure in and the elevation being saved to the database.
>
> --
> Andrew
> -------------------------
>
> FROM: Warin <61sundow...@gmail.com>
> SENT: 08 September 2017 02:59:39
> TO: tagging@openstreetmap.org
> SUBJECT: Re: [Tagging] Elevation in Feet as part of Peak Names
>
> On 08-Sep-17 09:10 AM, Dave Swarthout wrote:
>
>> Adding numeric values to the name of a peak is not okay. As for using feet
>> in the "ele" tag instead of meters, JOSM discourages this practice and I
>> think we should too. It's long past the time when Americans and other
>> countries still using archaic and cumbersome measurement systems based on
>> the length of the king's foot or thumb should embrace the metric system. The
>> down side is that very peak I add involves an extra step.
>
> Aviation still uses feet?
> Asking a mapper who may not be familiar with conversion into meters leads to
> errors. I'd rather have the render do the conversion as is done for other
> dimensions.
>
> Cheers,
>
> Dave
>
> On Fri, Sep 8, 2017 at 5:57 AM, Jo <winfi...@gmail.com> wrote:
>
> ele can of course be in feett or lightyears for that matter, but it's a lot
> easier to work with if they are all in the same unit.
>
> 2017-09-08 0:22 GMT+02:00 Warin <61sundow...@gmail.com>:
> On 08-Sep-17 07:39 AM, Shawn K. Quinn wrote:
> On 09/07/2017 04:31 PM, Mike Thompson wrote:
> User Raymo853 and I are having a friendly discussion on changeset
> 50470413[1]. He has been adding the elevation of mountain peaks (in
> feet) to the name tag. For example, he changed "Crown Point" to "Crown
> Point 11,463 ft."[2] While the wiki doesn't specifically address the
> issue of elevation as part of a peak name, it does say "Name is the name
> only"[3].
>
> Could we get feedback from the wider community on this? That's what this is
> for: https://wiki.openstreetmap.org/wiki/Key:ele [1]
>
> The only catch is that it has to be in meters, so you would tag
> ele=3493.9 in your example.
+1 to name tag is name only.
--------------------------
ele tag should be used for this information.
And I would think that the ele value can be in feet just like other
dimensional units of width, height etc.
Should this be put as a new proposal?
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--
Dave Swarthout
Homer, Alaska
Chiang Mai, Thailand
Travel Blog at http://dswarthout.blogspot.com [6]
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Links:
------
[1] https://wiki.openstreetmap.org/wiki/Key:ele
[2] http://wiki.openstreetmap.org/wiki/Tag:natural%3Dpeak
[3] http://en.wikipedia.org/wiki/EGM96
[4] http://en.wikipedia.org/wiki/Geoid
[5] https://lists.openstreetmap.org/listinfo/tagging
[6] http://dswarthout.blogspot.com
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