Shift in GPS track depending on wrist

As an avid heatmapper / run every street I'm particularly interested in more accurate GPS tracks.  I've been perplexed by why has appeared to be a shift of my GPS tracks to the left of where I run no matter what direction I run in.  So if I run an out and back on a road it looks like I've practically run a loop because its shifts it off the road on both sides.  In general my tracks are off the road and sometimes its more egregious than others.  I took to running on the wrong side of the road (with traffic instead of against) to get it more centered.  I then did an experiment and changed my watch to my right hand.  Low and behold my tracks started looking significantly better!  I figured there must be some sort of setting I was missing.  I found the wrist setting in my Fenix 6 and changed it from "left" (the correct setting) to "right" and it made no difference.  

Wearing the watch on my right wrist example here:  - I ran on the side of the road against traffic and its shifted to the right, which is closer to the middle of the road

Wearing the watch on my left wrist example: - notice how all the tracks are to the left where you would be running against traffic off the road

Really neither of these examples are very accurate as they don't capture where I really ran but at least with wearing it on the right hand it will actually show on the road I was running on.   I don't know if this is an intentional shift or not.  Also I'm not a fan of wearing it on my right hand (again wrist setting seem to make no difference in my tests).  Does anyone have any info on this?  

Also this isnt a one off test. All my runs with my Fenix 6 are like this and I found many with my Fenix 5 as well.  Additionally I have done several runs with it on my right wrist and they consistently produce better results every time.

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  • @Punch you're missing the point, I do not run around tall buildings or canopies.  It has nothing to do with that.  The technology is doing something different based on the directionality of the watch.  My tracks should look almost exactly the same if I wear on the right or left hand as they are only 1.5ish feet apart but clearly thats not the case.

  • They are both recent and both do not have tree cover.  TREE COVER HAS NOTHING TO DO WITH IT, THERE IS NO TREE COVER.  You guys arent reading my replies.  I'm telling you the technology behaves in a certain way based on the hand you wear it on.  Yes I have 1-second recording on.  I use the default GPS.  Yes zoomed way out it looks generally OK.  I use to track my progress and it is based on a certain distance to nodes that define a street so yes accuracy makes a difference.  When you run on the left side of the road and the GPS then shifts further to the left then it misses nodes.  Again I wear my watch on the right hand while running on the left side of the road it will show up quite nicely most of the time either close to the left where im running or in the middle of the road, obviously this varies a bit due to accuracy.  Basically what I'm saying is that I can run the exact same path out and back and it will end up showing a gap consistently because it will shift it to the left on both directions. This gap is even more defined if you run and out and back on opposite sides of a road (instead of say a sidewalk or the same side of the road each way)

  • I have the exact same problem. Left wrist signifantly worse track and shifted to the left. It  gets better when I run in completly open areas,  but as soon there is tree or building in sight it shifts to the left, sometimes by more then 30 m. It does not affect overal distance by much unless I run on track counterclockwise, my local 360 m metered track gets an average of 320 m.

    It then ruins all the data.

  • I noticed exact the same behaviour, see below, one run was left to right, the other one - opposite direction. Forgot to add that in both cases I run the same place, which is in the middle of both (closer to buildings).

  • those deviations are caused by the buildings 


    of course he does and you don't seem to understand.

    GPS satellites are not always  overhead and could be anywhere in the skies even low on the horizon therefore your signal decreases if you run adjacent buildings and canopies

  • If the new watches can't handle basic cul-de-sacs with one story houses and empty trees in the Winter without showcasing bizarre behavior based on the wrist I wear it on thats a problem.

  • When you wear the watch on a different wrist, there can be a difference in what it sees from satellites.  Your body will block some of the signal so it doesn't need to be buildings..

    When comparing GPS on more than one device, you probably want to wear both on the same wrist for this reason.  They both have the same "sky view" at the same time that way.  DCR did a post about how he does GPS tests some time back. 

    Another thing, is that GPS isn't correct down to the inch, and on good days, you're lucky if it's within a few feet.  That's why on some devices, there will be a "lock on roads" option, where using a map, the track stays on the road and doesn't go "overland"

  • I'm not sure I follow the logic here, because it doesnt matter which direction I run North, East, South or West.  The signal will not be blocked any more or less from either wrist.  Already covered the fact that I know GPS is not perfectly accurate.  Thats not the issue at hand.  There is a difference in the GPS deviating left and right because of accuracy and always being shifted left in the direction that Im running.

  • It could get down to how accurate your location is.  As i said, it could be off by feet.

    One more thing if you're viewing data in something like GC, check the "data recording" setting on your watch (Settings>System>Data Recording).  There are two modes - every second and smart.  Every second is just that. With smart (which is the default), it doesn't save the data as often - every few seconds based on your movement), so can restult in things like more cut off corners, etc,

    Do you see much of a difference in things like distance based on the wrist? (the watch always sees the GPS every second).

    Something like a difference of 0.0x is common, and 0.x0 not that unusual.