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fix tunel gps data

  • August 8, 2025
  • 1 reply
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During my activity today i crossed a tunnel and the GPS had issues with location, and that is affecting segments, as they appeared as excluded. Any possibility of fix? I tried to fix distance and refresh achievements but didnt work.

thanks,

joao

Best answer by ActivityFix

There isn't much you can do. GPS requires a line of sight to the sky so it doesn't work in tunnels. Usually what happens is you get a straight line between the last point and the next (when you exit the tunnel). I don't have experience with any tools that will let you edit the track on a FIT file though I know they exist. If you really want to adjust the track that would be your best option.

 

For example on this ride, the red line is my track but you can see the road in gray is a tunnel through the mountain. When I entered the tunnel I lost GPS and picked it up again when I exited so it's a straight line between the two points.

 

1 reply

ActivityFix
Superuser
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  • Superuser
  • Answer
  • August 9, 2025

There isn't much you can do. GPS requires a line of sight to the sky so it doesn't work in tunnels. Usually what happens is you get a straight line between the last point and the next (when you exit the tunnel). I don't have experience with any tools that will let you edit the track on a FIT file though I know they exist. If you really want to adjust the track that would be your best option.

 

For example on this ride, the red line is my track but you can see the road in gray is a tunnel through the mountain. When I entered the tunnel I lost GPS and picked it up again when I exited so it's a straight line between the two points.