S9 GPS altitude accuracy

DereksDontRun

I’ve recently started using my S9 for tracking my cycling instead of using my phone, and I’ve noticed a massive drop in height accuracy.

Comparing my results with mates on the same rides, their results all seem similar (obviously there’s some minor variability) but my height difference is always way below theirs:

recent rides:

plotted on ViewRanger - 22km with 630m climb
mates length: 23.76, 23.61, 23.77, 23.77, mine 23.15
climb: 646, 649, 647, 647 and mine 493m
plotted on ViewRanger - 22km, 760m climb
mate 21.89km with 776 climb, me 22.91km and 626 climb
ride (not checked on ViewRanger)
mates: 19.7, 19.92, 20.2 and me 18.86
climb: 388, 391, 398 and me 211
also not plotted on ViewRanger
mates: 22.5, 23.08 and me 22.26
climb: 543, 541 and me 289

Going back through them - the length doesn’t seem to be too bad, but the altitude change is pretty awful on my S9 compared with everyone else’s phones and non Suunto watches.

The watch is running the latest FW and I’m always running on Best mode with Performance battery and even made sure to use assisted GPS with the latest ride (number 4, where I recorded 289 vertical and others near twice that at 543 and 541).

I appreciate that the Baro watch is likely to be more accurate than the non, but surely the non baro should be similar to a generic smartphone (which is also missing a baro sensor).

Is my watch broken? It surely shouldn’t be nearly correct with the length (x, y position) but so wrong with the height? Is there anything I can do to improve it?

halajos

@DereksDontRun the barometer is not that uncommon in modern Android smartphones. If google’s API uses barometric pressure to calculate altitude (I have no idea if it does), then all GPS tracking apps take advantage of the sensor.

DereksDontRun

just seen it’s the same issue a reported:
https://forum.suunto.com/topic/3296/bug-of-positive-elevation-alti

so, seems a bug with the watch (and sounds like it was made worse with a FW back in Oct-ish?)

freeheeler

@DereksDontRun
you can also search the forum for altitude threshold… it’s not really a bug, it is to make the best without a baro that adds cost.
I think you’ll find plenty explanation here
but the summary is: if you are alti addicted like some of us, you might want to upgrade to a baro