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GPS about 30m off

Edwin
3 months ago

I have noticed this twice now. After using my GPSmap 67i for a few hours the gps is at once way off.

We went for a little walk this evening to find a cache. The gps worked fine until the last waypoint. We were on the right spot and according to the gps we were 30m away from that waypoint.

In the hurry of that moment I didn't notice the fault right away, but being home in my backyard I see the gps is still way off.

Multi-GNSS is selected and Multi-Band is on. According to the Satellite page  there could be a variation of 1.8m. On the map I can see the gps is at least 30m off.

Switching the device off and on solves it directly. I had the same experience yesterday (not caching or walking at that time, just playing with this new toy at home), so it is not just a one time glitch.

I wonder if someone else has this experience as well and I hope someone can tell me I can solve this behavior by myself.

Regards,

   Edwin.

  • 0 24 days ago in reply to jlg2

    Yes, thats exactly my experience. In parallel I had my old Oregon 450 running, and there are all points within a radius of 5 to 10 meteres except from a few outliers. And even the outliers are only 20 to 40 meters away from the center. There are also just 1 or 2 points, then its fine again.

    With some further testing on the GPSmap I found out, that when I turn off Multi Band and Multi GNSS, the behaivor is better, but still present.

  • 0 24 days ago

    I checked my 67i (ver. 8.80 firmware) today for three hours in a stationary location with multi-GNSS enabled and with about 3/4 of the sky hemisphere unobstructed.  The 1 standard deviation uncertainty was 0.77m from the mean (normal PDF).  Of course, I have only a vague idea of the true location.  But what I know is that of 341 points recorded, half were within 1.75 m of the mean; 3/4 were within 2.71 m and all were within 4.3 m of the mean. 

    I assume those who are recording strange drift much greater than that are not measuring during an earthquake in Katmandu or testing near the GPS spoofing along the battle lines in Ukraine.  So you should probably be talking to Garmin support and telling the rest of us what you learn.