Bug: Strange spikes in altitude data

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Anna Ronkainen

• April 11, 2022 10:15
• Edited

My elevation gain numbers are nonsense because of spikes like these in the altitude data:

For instance both of these rides recorded over 1000 m of extra elevation gain compared to the numbers shown by Komoot for the same routes. This has been occurring on a regular basis for quite a while, but somehow it only happens in the Berlin/Brandenburg area, whereas altitude data for rides in southern Finland looks quite normal, so I’m wondering if these spikes are somehow connected to the map data.

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  Anna Ronkainen

  • April 11, 2022 10:23

  Looked at the data in TrainingPeaks as well and most (but not all) of these spikes seem to be associated with sudden changes in temperature:

  

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  Edgar Karel

  • April 11, 2022 11:53

  Interesting observation, since HH calculates elevation via a barometer. And temperature will influence the barometer.

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  Anna Ronkainen

  • April 11, 2022 13:09

  Yeah, that’s what I thought as well. Still, it being anything weather-related doesn’t make any sense to me, because here’s another ride from about two weeks ago in extremely challenging weather (wind gusts well above 20 m/s, should not have stopped reading the forecast at “no precipitation”...) in Finland, and the temperature and altitude data seem completely normal (apart from the lack of altitude calibration):

  

  

   

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  Ali

  • April 13, 2022 08:22

  Hi Anna, we are working on smoothning and filtering out the spike with the elevation data. May I know if you were using the SIM card on your Karoo without or without a cellular data ON?

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  Anna Ronkainen

  • April 13, 2022 08:28

  Thanks for the info. I generally have cellular data on (including on these rides), except when there might be a risk of downloading additional (unnecessary) offline maps (I think this one has been fixed but I’m still a bit paranoid about it).

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  Ali

  • April 13, 2022 08:48

  Anna, could you disable that on your next rides and see if this still continues to happen? We are still working through these as it has been challenging but we are committed to get it solved.

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  Anna Ronkainen

  • April 13, 2022 09:00

  Ok, I’ll try it, but again this only seems to be happening to me in Germany (and not Finland; mobile data on in either case), which is kind of strange.

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  Anna Ronkainen

  • April 13, 2022 15:46

  I checked that I have automatic calibration on (must have somehow failed in the ride that was recorded as being all below sea level) and it says something about using the internet connection and what else, is the unit really doing something too smart for its own good in terms of altitude calibration? I would think that doing it at the start of the ride (or once every 3–6 hours) would be enough, after all we’re not trying to land an airplane here or anything...

  Anyway, I’ll try both turning the mobile data off and switching to manual calibration.

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  Anna Ronkainen

  • April 30, 2022 14:57
  • Edited

  More experiments done (expected altitude gains according to Komoot, with some margin off error due to deviations from planned routes):

  1. mobile data on, automatic calibration on: 500–600 m expected, 2372 m recorded
  2. mobile data off, automatic calibration on: 250–350 m expected, 450 m recorded
  3. mobile data on, automatic calibration off: 350–400 m expected, 1617 m recorded
  4. mobile data off, automatic calibration off: 300–400 m expected, 628 m recorded

  I guess the winner is option number 2.

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  Steve MacMillan

  • May 02, 2022 09:42

  That is a very disheartening set of results! Thanks, Anna, for taking the time to do those tests!

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  Antonio Prado

  • August 09, 2022 15:54

  The same is happening to me. I'm getting mistaken altitude numbers due to the peaks.
  I'm using sim card with data on

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