GPS Accuracy

Yesterday I had a run using my fenix 6x sapphire and my Polar V800. A friend of mine used his fenix 3HR. The result after a 10 km run was that my Polar V800 stated 10,05 km, the fenix 3HR 10,00km and the fenix 6x: "9,51 km". Deviation of 5% !!!

Reading the gpx-data and evaluating the distance gave a result of 9,95km.

Garmin WHAT ARE YOU DOING????

Run 5km (1 circle is 230m) with Fenix 6 saphire titan, firmware 4.30, GPS firmware 2.60, Run settings with GPS+Galileo, record every second:

the distance was more accurate than it was with GPS firmware 2.50

What's weird that on my activities the track is most of the time about 20m off to the left. Here a some examples activities:

https://connect.garmin.com/modern/activity/4275140575

https://connect.garmin.com/modern/activity/4266501074

https://connect.garmin.com/modern/activity/4257082557

fenix 6 Pro / Sapphire, worn on the left wrist, different firmware versions and GPS settings.

Think of it like this, say your walking around a circle; in smart mode it it's save memory by recording fewer points if your traveling straight vs a complicated path.  So a straight line path might record a few points, where as a circular path might record say 10 points. Now switch to every second recording the watch might record a hundred points depending on how fast your traveling and the size of the circle. A 10 point circle looks pretty blocky vs a hundred points which would start to look like a circle.

Another Run 5km (1 circle is 230m) with Fenix 6 saphire titan, firmware 4.30, GPS firmware 2.60, Run settings with GPS+Galileo, record every second.

The kilometers marks are less true than at the previous run. I had to run longer to reach 5 km. Although at a circle of 230m, running 4 laps (920m) I still have 80 m to complete the next kilometer. Ideally, the distance between the kilometers points should be 80m.

shaunmcd said:

Think of it like this, say your walking around a circle; in smart mode it it's save memory by recording fewer points if your traveling straight vs a complicated path.  So a straight line path might record a few points, where as a circular path might record say 10 points. Now switch to every second recording the watch might record a hundred points depending on how fast your traveling and the size of the circle. A 10 point circle looks pretty blocky vs a hundred points which would start to look like a circle.

Right, I understand how it works and I understand what you're saying. But what I'm saying is that the distance recorded to the activity won't change, regardless of the resolution of the recorded track.

A common misconception is that smart recording causes the watch to take fewer and less-frequent GPS location readings. It doesn't. It only selectively saves those readings to the FIT file. But it still uses every single reading (even those that weren't recorded to the FIT file) when calculating the distance for the activity. Garmin has clarified this previously. Smart recording vs 1-second recording has no effect whatsoever on the distance that your activity will report. It only makes the track get drawn with higher resolution. Smart recording has no affect whatsoever on battery life or distance calculations, the only thing it does is reduce the file size of the FIT file.

Garmin is aware of the fact that smart recording would be completely useless if the distance reported by the activity was based on the choppy low-resolution track. So they don't base the distance on the track recorded, they calculate it based on the actual distance traveled.

Run 5km 24.11.2019 (1 circle is 230m) with Fenix 6 saphire titan, firmware 4.30, GPS firmware 2.60, Run settings with GPS+Galileo, record every second.

where number 5 is looks like gps was Lost. the track is off the path and you have clear sky lol. Brutal. How much off was the distance in total?

I dont know, but here you can see the scale.

Another explanation could be that the tracking is "mostely" within the spec. but the watch looses GPS connection for 250 meters or 80 seconds and then connect the dots afterwards.