Does Potlatch3 distort tracks uploaded to OSM?
tracker51 opened this issue · 4 comments
Since a few weeks I use a new GNSS device for recording my tracks (10 measurement per second). These tracks are astonishing precise because they are real-time corrected by SAPOS data.
The more disappointing is how the uploaded to OSM tracks are shown by Potlatch: totally distorted:
How come? What am I doing wrong? Any help is really appreciated.
Best regards
tracker51
Can you point to one of your tracks as uploaded to OSM (ideally set to public)?
Ah, I think I see.
A few years ago a change was made to the OSM API relating to unordered GPS traces. openstreetmap/openstreetmap-website#2046
If you upload a track as "public (shown in trace list and as anonymous, unordered points)", i.e. without timestamps, then the OSM API doesn't guarantee the ordering. As a result, in order to show a trace, P3 has to retrofit a likely ordering. This will potentially break things in the way you illustrate.
I think there are two ways you can avoid this:
- Upload your traces as "Trackable" or "Identifiable". This means P3 can use the ordering from the file you upload.
- Manually load your GPX files into P3, so you're not reliant on the behaviour of the OSM API. P3 will then trust the ordering in the file. You can do this with "Background" -> "Vector file" -> "File: Open..." (choose GPX).
Hello Richard,
Many thanks!
Best regards
tracker51