Page 1 of 2

Issue with elevation with Wahoo fit file import

Posted: Wed 6. Jun 2018, 12:14
by matsalo
When importing fit-files recorded with wahoo fitness app (android), I got an issue with elevation. First minute in every import has elevation set to zero. In the plot I started and ended at same spot, but has a elevation difference of 90m:
elevation.jpg
elevation.jpg (24.14 KiB) Viewed 2532 times
And just to illustrate it, this gives a prety impressive climb score...
climb score.jpg
climb score.jpg (68.13 KiB) Viewed 2532 times
When looking at other export files from the Wahoo app, e.g. the gpx shows that no elevation data is recorded the first minute. So I guess this can be a reason. But all other platforms and applications where I import the workouts handle this just fine.


Is it a way to correct this in runalyze?

Re: Issue with elevation with Wahoo fit file import

Posted: Wed 6. Jun 2018, 13:54
by laufhannes
Currently there's no way to manually edit the elevation profile. There's only the option for 'elevation correction' which will generate a new elevation profile based on satellite data (only possible if gps coordinates are recorded). But maybe there's a chance to automatically fix this issue while reading the file. Can you provide an example file such that we can take a look at it?

Re: Issue with elevation with Wahoo fit file import

Posted: Wed 6. Jun 2018, 14:45
by matsalo
Thanks for your swift reply.

I have attached one fit file (2018-06-06-081740-UBERDROID727C-17-1.fit) for the workout mention earlier.

Re: Issue with elevation with Wahoo fit file import

Posted: Wed 6. Jun 2018, 18:35
by mipapo
mh, I don't see the attachment?

Re: Issue with elevation with Wahoo fit file import

Posted: Wed 6. Jun 2018, 20:16
by matsalo
Strange, was there last I checked.

New try :)


Edit; attatchment removed

Re: Issue with elevation with Wahoo fit file import

Posted: Sun 10. Jun 2018, 10:55
by matsalo
The issue appear to be that the track is outside the satellite data coverage available (north of 60 degree north), and therefor could not be corrected with a new elevation profile, and further the gps elevation profile lacks data point in the start of the profile.

Is the easiest fix with gps elevation profile without full track coverage just extending/extrapolate the profile to full cover? I would assume a horizontal level with a actual value for some hundred meters are in most (any?) cases more correct than zero. My concern isn't to have a super accurate elevation profile, but the impact a jump from zero to actual elevation has on calculations as e.g. VO2max if it has elevation correction.

Re: Issue with elevation with Wahoo fit file import

Posted: Sun 10. Jun 2018, 18:40
by laufhannes
I definitely have it on my list. The 'easy' fix is what you mention: Assume a constant altitude. The better way is to correctly display that there's no data for that segment. Null values should be saved in the database, but so far none of the algorithms ignores these null values (plot, total elevation, climb score, ...).

Re: Issue with elevation with Wahoo fit file import

Posted: Mon 11. Jun 2018, 07:55
by matsalo
Have you done any changes lately? When I imported todays run, I got the impressive 360.67 VO2Max and felt quit stunning :o

The reason is that I have the usually lack of elevation data first 200m, and if elevation correction is ticked on it was corrected to -10 000m and put a message "elevation data were corrected". This is new of today, earlier I only got the message that elevation data could not be corrected and the checkbox for elevation correction had no real function. I ticked off elevation correction and we are back to normal with zero elevation in the start.

Just tough let you know since it was a new experience of today.

Keep up the good work you doing, it's awesome.

Re: Issue with elevation with Wahoo fit file import

Posted: Mon 11. Jun 2018, 08:21
by laufhannes
We've added another source for elevation data (Aster data from geonames.org) which has data for your latitude. I've created a small example to check its functionality and that was okay, but it seems that not all data holes are filled correctly.

Can you append or send us your recent activity such that we can check which exact values are returned by the data provider?

Re: Issue with elevation with Wahoo fit file import

Posted: Mon 11. Jun 2018, 09:12
by matsalo
I've attached the workout file. This is how it looks like to me in two import with and without elevation correction:



Thanks for your effort :)