[gdal-dev] Add elevation data to gpx files

[APM]

Dear List,


I like to add elevation data to some gpx files by using ogr directly.


The actual files are containing for example:


<trk>
   <name> town </name>
    <trkseg>
     <trkpt lat="xxx" lon= "yyy"/>


etc ....


Before I asked I created a point layer with DEM data in Qgis 3.22.3. by 
using the "Point sampling tool" and

imported the gpx.

I use http://www.viewfinderpanoramas.org/ as DEM source and create a 
.vrt Raster from it.

Now I have a shape which is containing two attribute fields "fid" and 
"dem", which shows correct DEM data according to the gpx-points.


But I can't create an assembled new gpx file which include something like


<trkpt lat="xxx" lon="yyy"/>

<ele>210</ele>


etc...


I would be glad for some help!


Thank you very much!


Kind regards


Piet