Problem of cumulative elevation gain
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Good evening everyone,
Friday I ran the Endurance trail of the Templiers in Millau, 105.6 km and 5300 m of D + according to the organizer and the trace on Trace de Trail.
On arrival, my Suunto 9 Baro gives me 109.6 km and 4287 m of D + !
Normal for the difference in distance, it is classic with all the watches because of the refuelings.
But how to explain this final difference of 1000 m of D + ? It’s huge !
We do not talk about a few tens of meters, which can be conceived, but there 1000 m it becomes annoying, including to know what it remains to run in D + !
I had synchronized my watch in the morning before leaving, so normally AGPS was update.
Does anyone have an explanation ? -
@PatBess said in Problem of cumulative elevation gain:
Endurance trail of the Templiers in Millau
Does the recorded path match the “official” one ?
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@sartoric Yes, exactly.
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That’s strange
If you import it in some route planner like GAIA , Komoot or similar , what’s the ascent calculated ? -
@sartoric I’m gonna try.
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@TELE-HO Unfortunately I do not manage to import the .fit file in GAIA !
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@PatBess said in Problem of cumulative elevation gain:
@TELE-HO Unfortunately I do not manage to import the .fit file in GAIA !
You should import it from the “Track” menu (anyway, it should be the same as “import”)
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@sartoric My file can’t be imported ! It doesn’t work.
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@PatBess
Maybe the fit file is too big.
You could try to save the route (from activity menu) and then share it (from routes menu) to save it.
Probably you’ll need to use some google drive as a temporary solution or you can email it to youIt’s a bit tricky, I know, but it’s for the sake of knowledge
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Here is an illustration of how Suunto 9 ignores a lot of smaller climbs even though they exceed the 3 meter (10 ft) threshold. This is a screenshot of elevation profile from my today’s short run with a dog. Just to be clear, this is exactly what the watch barometer has captured, so I am comparing the watch absolute altitudes to the total ascent that it counted for the same run. All altitudes are in feet:
Here are elevations at a few points into the run where the vertical direction has changed in excess of the 3 meter threshold:
Start: 203 ft
1’22: 187 ft
4’16: 205 ft (18 ft gain)
5’08: 193 ft
6’16: 216 ft (23 ft gain)
10’54: 128 ft
12’14: 140 ft (12 ft gain)
22’38: 110 ft
26’32: 195 ft (85 ft gain)
27’22: 185 ft
End: 214 ft (29 ft gain)Adding all small gains the total comes to 167 ft.
The watch shows only 112 ft total ascent. I think the watch has counted only the final climb from 110 ft to 214 ft and perhaps a part of the climb in the beginning. For comparison, Strava shows 187 ft, which is too much but still closer to the reality than the Suunto’s low number.
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@silentvoyager
I never noticed this before as I normally go one bigger uphill, then downhill… looks like s9b can’t handle intervals up/downs not consistentliving sideways
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@silentvoyager so it’s not necessarily a problem with the +/- 3m threshold but rather the way the algo is actually handling the changes?
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@TELE-HO @silentvoyager @stromdiddily I have noticed this issue on smaller ascents/descents as well. I normally do much bigger climbs and descents, on the larger ones the S9b does a very good job. Would be interesting if it was the app and not the watch.
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@Brad_Olwin In the S9B diary, the elevation is not right, so it’s the watch, not the app. Should an algo correction improve cumulative elevation accuracy ?
How can we explain the issue to Suunto ? -
@PatBess
I’m not 100% sure but I think @Dimitrios-Kanellopoulos knows this kind of issue already and might have forwarded it to the developers. It’s not a brand new discussion for my info. We’ve had in mainly for non Baro watches where the offset is much bigger -
@TELE-HO yes, it has been discussed, and someone (sorry I could not remember who) give some ideas for improvements… I think it has been passed to developers, but how knows… anyway it seems to be not so easy to include this little up/downs… for me it’s annoying, because my Suunto has no baro, so there must be ¿7m? of elevation to accumulate it…
Ahh now I could remember that some of us, say that we will be happy signing a NDA and testing new FW with changes for this issue
BR
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@Brad_Olwin said in Problem of cumulative elevation gain:
@TELE-HO @silentvoyager @stromdiddily I have noticed this issue on smaller ascents/descents as well. I normally do much bigger climbs and descents, on the larger ones the S9b does a very good job. Would be interesting if it was the app and not the watch.
The error is proportional to a number of climbs rather than the total ascent, and my estimate that it is on the order of 3 meters per climb. So if a run consists of one or two big climbs the error is relatively small to not be noticeable. But if a run goes on rolling terrain with constantly going up and down the error accumulates quickly.
In my custom trail running mode for small to medium runs I have total ascent next to the current altitude on the same screen, so I often watch the two metrics together.
I can tell you that the total ascent increases in chunks and with a noticeable delay. For example I keep going uphill and I see that the altitude goes up but the total ascent stays the same for awhile, then increases by 10-12 feet (3-4 meters). If I crest a hill quickly it doesn’t capture the last few meters of the climb. But I noticed that if I stop at the top and wait for about 5-10 seconds then the total ascent may go up.So it is definitely the watch itself that does some sort of delayed averaging in addition to the threshold to filter out small pressure changes. But I think the way watch does that is overly conservative.
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@silentvoyager yes I think it’s 3m for baro, and 7m for non baro units (or something similar)…
