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GPS fail / spike

PEPITO82
over 4 years ago

Hi all,

on my yesterday's run I had a negative experience with GPS. 
It was a structured training from my training plan at training peaks.
First 1:05 h easy running, then 4 repeats with strides followed by 6 minutes of cool down.

Just a few seconds before the end of fourth break - watch started to beep already - I stopped recording because I reached bakery.
After one minute of shopping, I pressed resume I got warning that I'm too quick - speed someting around 1:20 min/km.
But I was continuing at about 5:30 km/min pace until the starting point.

Back home the track of the activity looked like this - having a big spike to a place a couple of km away:



https://connect.garmin.com/modern/activity/4427422599

The weird thing is that I saw somthing similar at a friends track on Strava.
Has anyone else experienced such behaviour?

Regards,

Peter

  • 0 over 4 years ago

    It is a classic case of very bad multipath error. If you are not the only one with similar experience, that means something in atmosphere wasn't kind to GPS signal. Common thing on the very cold day.

  • 0 over 4 years ago in reply to bane.lukic

    Well, that isn't very cold, just minus couple of degrees and haven't seen so bad in any years before. Granted haven't used 945 yet on winter runs, so yet another crappy thing to be expected from Sony's chipset or it's not as common as you say it is? :) 

  • 0 over 4 years ago in reply to jmto

    If it is below zero, there are plenty of icy crystals on the ground and in the air. More than enough to create suitable environment for GPS multipath errors. This is just limitation of the current technology. Just to be clear, these kind of errors are rare, but I've seen GPS "teleportations" more than 20 kms away.

  • 0 over 4 years ago
    PEPITO82 said:
    The weird thing is that I saw somthing similar at a friends track on Strava.

    What device did your friend record his track on? Would be interesting to know what GPS chipset he has .

  • 0 over 4 years ago in reply to philipshambrook

    Just got feedback from him. He has a Vivoactive 4.
    So it could be an issue with the Sony GPS chipset...



    Before the 945 I owned almost 2 years a 935. Never experienced such a GPS fail in the past.
    Despite running at low temperatures as well.