[Talk-ca] workflow for elevation data

[Charles Basenga Kiyanda]

Thanks all for the replies. (I'm replying only to Richard here, but I've 
read each and every one.) At the point, the project is a demo that I 
want to do and try to impress  people with, so the objectives are really 
mine. What I wanted was to show the leaflet-based slippy map and when 
the user hovers/clicks on a given track, the elevation profile is 
displayed somewhere in a pop-up/frame/etc. Something close to this example:
http://mrmufflon.github.io/Leaflet.Elevation/example/example.html
(I think it's using geojson here.)

The hope was that I would convince them to also contribute the path 
information to osm, though most likely, that would require they maintain 
the data in two places: osm and their local gpx/geojson files with 
elevation.

I've read somewhere that the srtm data has, at best, 30m resolution. I 
don't know that it's resolved enough for 
hiking/snowshoeing/cross-country skiing? I can think of features where 
greater than 30m resolution would be helpful. Then again, I just looked 
at opencyclemap for that area again, and the resolution might be plenty. 
I'll have to look again.

Cheers,

Charles

On 02/23/2014 04:40 PM, Richard Weait wrote:
> On Sun, Feb 23, 2014 at 3:42 PM, Charles Basenga Kiyanda
> <personal at charleskiyanda.com> wrote:
> [ ... ]
>> Specific question:
>> We don't store elevation data in osm in a standard fashion and I was
>> hoping I could show the volunteer organization a tentative alternate
>> workflow that would be as little work for them as possible and also give
>> them an incentive to keep the osm trail data accurate.
> I think that the main issue here is "how do they want to see / use the
> elevation data?"
>
> There are several existing styles / tiles that use contours and or
> hill shading.  There may also be contours and hill shading that are
> available as overly layers for you to add to your own styles.  (If
> their aren't, that may be an idea for a value add service. ;-) )
>
> There was a service, run by long time OpenStreetMap user lambertus,
> that displayed an elevation profile graph of a selected way.  That
> specific source is gone or moved now, but this wiki page shows some of
> the similar details from a related summer of code project.
>
> http://wiki.openstreetmap.org/wiki/Route_altitude_profiles_SRTM
>
> It also appears that the routing engine YOURS can interpret elevation
> data to apply variable costing when evaluating or planning routes.
>
> http://wiki.openstreetmap.org/wiki/YOURS
>
> And there are certainly more things that we can do with elevation that
> are interesting, depending on the audience.
>
> Is that enough to get you started?
>
> But, yeah.  The elevation data doesn't go into the OSM data base.
> Others have used SRTM to inform their OSM objects of elevation matters
> and then done interesting this with it.
>
> I gave an Intro to OpenStreetMap talk to some trail folks recently.
> It would be great to see them contributing to and benefiting from
> OpenStreetMap.