Distance accuracy

I have been wondering about the same, for another reason:
When I walk in a straight line, my watch shows a slower pace while I am walking under tree cover or along tall buildings.

Logically, if the watch was just "connecting the dots" between the GPS coordinates, and those dots became more random due to bad GPS reception, the measured distance would be longer, causing my pace to appear faster, not slower.

So I guess that the watch (or an algorithm in the GPS chipset itself) is applying a correction factor depending on the quality of the GPS reception. In my case it appears to be overcorrecting, so when measuring a too fast pace due to bad signal, it will correct the measurement so much that the pace becomes too slow instead.

I have only done one walk with v2.24, so it is too early for me to say if this behaviour has improved.

My Fitbit Ionic consistently shows 5-7% longer runs than my Fenix 5S Plus. Anyone have a similar experience?

My Fitbit Ionic consistently shows 5-7% longer runs than my Fenix 5S Plus. Anyone have a similar experience?

Yeah, this is similar to what I have found when comparing my 5x plus to most other devices. 5x plus is usually 5-10% less (sometimes up to 15%). I'm still not completely sure if the Fenix is short or the others are long. I think the Fenix doesn't have very accurate distance in tighter, tree covered trails. On the other hand, if you analyze and compare tracks closely, the Fenix tracks usually look a lot cleaner.

Hi all,

Today I've observed something quite interesting regarding total distance of an activity.

I've tested gps version 2.20 vs 2.24 by doing the same 5k walk twice on the same day. The gps version 2.20 had a lot of drunken man syndrome which was not present in version gps 2.24. A clear improvement. So I was expecting the total distance for 2.20 to be longer than for 2.24. However, both were exactly the same (5.3k).

However, I've imported both tracks to Basecamp and the real distance for 2.20 was 5.5km while for 2.24 was still 5.3km. The drunken man syndrome equated to an extra 0.2km. Therefore it looks like Garmin applies some sort of smart algorithm to estimate the true distance. That's why when people look at Strava vs Garmin it looks like the Fenix 5 is always tracking shorter while in fact might be more accurate.

This is just a 1 off test but there might be something here.

Let see what others think.

I went for a run yesterday and everything started out great (the paved trail has mile markers). I hit the .5 mile and the watch says .5 then something happened I have no clue, but every half mile after that was off by .2 so the next half mile the watch said .7 and so on. So by the end of the the fun it was a whole quarter mile longer than the actual run was.
Has anyone else had this happen? GPS firmware is 2.24.

Same issue guys.
Yesterday on a 11K trail that i did dozens of times with several different watches and phones, the 5 plus marked ca. 300 m less.
The distance is consistently less than other devices of my running partners, around a track it marked ca. 20/30 m less over one K.
Might not seem much, but to me it is.
Garmin honestly literally s c r e w e d - up with this device, it's my fifth Garmin and it's horrible for running and for golf (reason why i bought it); on top, they don't care about consumer feedback and never reply, if not with standard pre-compiled answers.
A Joke, really - i'm starting to strongly recommend all my friends not to buy it.

Since the purchase of my 5+ I went through a couple of updates currently being at 4.65 and GPS 2.24. During that journey I ran some 400km, mostly using either a Vivoactive HR in parallel or running on tracks of well known distance. I tested all combinations of GPS, Glonass and Gallileo. My summary is the following:
- GPS accuracy improved to a certain degree and is under normal conditions staisfactory
- That means it is not perfect, but it is consistent over time withe some error averaging out and being better than 1%
- Positioning at the start is a lottery of +/- 50m, even with 5min of waiting and more
- It doesn't really make a difference, which combination of positioning systems I use or if I use GPS alone
- If you run in not so perfect conditions like forrests (even with a thin leave cover) or overcast sky tracking gets worse. On half marathon partly through a light forrest I lost 700 of the 21.100 meters
- Picking up the track after having passed through GPS-shadows (short tunnel) can fail with a significant offset and then taking a few hunderd meters to recalibrate
Conclusion
- My engineers guess is that the GPS is by design less acurate than that one of the Vivoactive HR
- Even with software engineering you probably won't break through these limitations
- Knowing these limitations I know when to trust the 5+ an when not (and taking a smartphone as backup tracker)
- Nevertheless it is a shame that an 800€ watch performs at a lower standard then the Vivoactive HR for which I paid a thir of the price at those times.

To the benefit of the 5+: With all other features like Music (Bose Sundsport), Navigation, Fitness, etc. I am pretty fine - No objections here!

Allan, I had the same feeling with my Fenix 5.
The track shown on the map was more or less correct, however, the distance has been measured too short by 4-11 %. per kilometer and obviously total distance. For this reason I returned the watch and want to get the F5+ now but just keep reading things about bad gps accuracy. :-(

Did the same run with my new Fenix 5+ with GPS and Galileo. Distance was measured absolutely fine. Also the pace shown and reported via headphones always made sense. Finally happy now.
I was happily impressed as I expected just the same bad measurement as the Fenix 5 did before in every run.

Did the same run with my new Fenix 5+ with GPS and Galileo. Distance was measured absolutely fine. Also the pace shown and reported via headphones always made sense. Finally happy now.
I was happily impressed as I expected just the same bad measurement as the Fenix 5 did before in every run.

Good news! What firmware are you using?

Software 4.20, GPS 2.20
Will do further tests and compare as I have measured all different tracks in my local forest. So far it measures the same as my Edge, Forerunner 735 and Google Maps. Fingers crossed!