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I am trying to refine/populate gpx tracks recorded by a GPS device. I would like to add 1 or 2 points between each gpx point recorded and snap these additional points to roads.

I am using essentially QGIS. Any suggestion how I could do this?

This issue is also discussed in this topic how-to-create-an-exact-tracking-route-from-gps-data.

As mentionned in one answer, the problem is called map matching.

  • It is just an idea, but you can export the gpx track to a shape file, then densify the lines (vector/geometry tools), then export the shape to gpx again. – Gerardo Jimenez Aug 24 '15 at 2:02
  • That was what I had initially in mind, but in curve for instance, I do not know how to proceed to keep/project the new points on the road network. – kFly Aug 24 '15 at 22:26
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  • For clarity, you want to end up with line features where the original GPS points might not be snapped to roads, but the additional interpolated ones are? And how do you decide if you want one or two extra ones? – Spacedman Sep 3 '16 at 7:32
  • As first thought, I wanted to keep the original points and set at the beginning of the process the number of points to be added in between these original points. The tricky part is to have these additional points snapped on roads segments, especially on curves. I could also accept to work with original points moved on roads, and the additional points added after but still on roads. – kFly Sep 6 '16 at 21:47
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You can do this and more prior to importing into QGIS with a tool called GPS Track Editor (www.gpstrackeditor.com) It allows you to merge (from simultaneously running gps units), restructure, increase frequency (densify), reverse and filter for local inconsitances. A great free utility.

  • Thank you for link. The editor is doing track densification, but I haven't see a process to snap the points on existing roads. I am missing an option ? – kFly Sep 5 '15 at 8:57
  • i don't think this utility has this capability. my workflow has been to use the editor for merge, densification etc saving the new gpx file. I then import as vector layer to QGIS, save that as shp file (i select add to map as new layer). The shp file of the points can then be enabled for editing and then the points can be individually relocated using edit>move feature. – wstewart1958 Sep 8 '15 at 18:52
  • Thanks much for letting me know about this app. Just solved me the problem how to turn 2-3 second GPX to 1 second and "increase frequency" worked great. :-) – Juhele Mar 19 at 14:25

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