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[SOLVE] Elevation data become wrong when I start an acivity

kekelamalice
over 4 years ago

Hello everyone.
Since a few weeks, I'm facing of an elevation issu when I start an activity from my home.
I live at 200 meter, my altimeter is correctly calibrated. But when i start an activity from this particular place, the elavation goes up to 1650m...

Of course if I desable the Auto calibration option in my watch, there is no more problem. But I would like to keep it enable.

I think i read something about DEM point and manual calibration that would be saved as a data on the watch, but I can't find it anymore.

What do you think about that ? 

Thanks.

EDIT--------------------------------------

Thanks to Volker, here is a very interesting link : 
https://support.garmin.com/

Here is what Garmin say about Auto calibration priority at the start of an activity : 

At Start - The goal of "At Start" calibration is to provide a consistent relative starting elevation for users that do multiple activities at specific locations. It will not calibrate again during the activity. When the timer is started the watch will try to determine the best elevation source to calibrate to, based on the following priority:

  1. Manual calibration immediately prior to starting the activity
  2. Prior manual calibration point at the same location
  3. Recent manual calibration, if the quality of the calibration is determined to be good enough
  4. Map data (DEM), if available
  5. Prior Connected DEM point at the same location:
    • Connected DEM refers to elevation data from the Garmin Connect app on a paired smartphone
  6. Connected DEM, if currently connected to a phone
  7. Prior GPS point at the same location
  8. GPS, if a good fix has been acquired:
    • After acquiring a GPS fix the timer ring will turn yellow. At that point, it can take up to 30 seconds for the GPS elevation to settle. If vertical speed settles to less than .1 m/s the GPS elevation data will be considered good enough use for altimeter calibration.
    • Before starting the timer, the elevation data field on the watch will preview the calibrated elevation

EDITn°2 --------------------------------------

I fixe my problem by doing an elevation calibration using GPS, at the place where the previous value was wrong. Now everything is ok.