Problem of cumulative elevation gain

Brad_Olwin · 22 Oct 2019, 02:13

@silentvoyager said in Problem of cumulative elevation gain:

@Brad_Olwin It isn’t a difficult issue at all. I’ve described the algorithm in details in my post (linked above) and it can be described in just a few sentences. By the way, I am a developer in a very well known software company myself.

I know you are and I am not a software developer so definitely out of my league here. I agree that the averaging may be overly conservative as you posted below. However, if less conservative do you believe it would then be more accurate? I know enough about the testing to suspect that different averaging approaches were likely attempted.

Typically I watch total gain and elevation on long climbs that are not very fast so I do not see the delay in averaging. In non-baro watches the situation is much worse. Unless I am doing a big climb the elevation gain/loss is typically well below the actual value.

stromdiddily · 22 Oct 2019, 02:47

@silentvoyager can you walk me through how your proposal would handle a point to point route of 3m up, 2m down every 10m over 100m run?

Unless I’m reading it wrong, you’re suggesting that the “going down” calculation doesn’t kick in until you’ve triggered the min threshold from your “recent high” reading. Wouldn’t this end up with 0m descent over my example run?

A Former User · 22 Oct 2019, 03:37

@stromdiddily Do you think the current algorithm would produce non zero descent? It would be good to try but I doubt the result would be any different.

A Former User · 22 Oct 2019, 03:51

@stromdiddily Just to give you one specific example - not exactly what you are asking for but something that I’ve actually done. I once had hill repeats on a very small hill where I went up and down about 5 and half meters - that was the difference between the high and the low points based on the elevation profile. I didn’t have any better hills in that area. I went up and down 30 times. My Suunto 9 counted only 90 meters of total ascent and 90 meters of total descent.

freeheeler · 22 Oct 2019, 06:20

@silentvoyager
I’m not a software developer either, pure mechanics… but would it be possible to count every meter, store it and smooth the graph later with doublecheck of the independently stored gps alti graph?

Fiox89 · 22 Oct 2019, 06:50

On a recent excursion I noticed that the watch (suunto spartan) correctly records the right total elevation, but when it goes to synchronize the track on the application this is different. Also, the track log on the watch shows a different measurement, once the activity is interrupted, the same as the app.

From what I understand, the problem occurs when the recording of the activity is interrupted, so it is in the post processing of the data. Can anyone confirm?

Dimitrios Kanellopoulos · 22 Oct 2019, 12:35

@Fiox89 no post processing of data is done at all

freeheeler · 22 Oct 2019, 12:43

@Dimitrios-Kanellopoulos
then smoothing the graph isn’t possible either as I understand…
there will be different options.
Suunto teams will solve that, I’m sure

FredMt · 23 Oct 2019, 07:17

@silentvoyager

Yes i think your right, i practise running stairs. I have stop using elevation by suunto 9 baro because it was permantly under the reality. I used to do it by myself on movescount web site…, but now with Suunto app, it s impossible, elevation fields are not accessible in modification…

A Former User · 26 Oct 2019, 06:21

Also I suspect that on Suunto 9 FusedAlti makes the total ascent and descent less accurate. I think that when FusedAlti kicks in and adjusts the altitude, that isn’t properly reflected in ascent and descent calculations and may artificially increase or reduce ascent / descent numbers.

There is one run near my home that I tend to do a lot. That is a short 3.2 mile loop (just over 5 km). I ran it over 50 times - with Suunto 9 and earlier with A3P.

Looking at Suunto 9 Ascent / Descent numbers I see that the ranges or ascent and descent are greater and the difference between ascent and descent for any particular run is also greater.

More specifically ascent ranges from 188 to 246 ft, descent ranges from 184 to 259 ft, and the largest difference between ascent and descent in the same run is 50 ft (~ 17 meters).
The explanation that I’ve heard before is that due to the weather change.

However when I looked at earlier runs with A3P I’ve never seen a difference between ascent and descent for runs on this route greater than 10 ft (~ 3 meters).
The values in general seem to be distributed more tightly (with fewer outliers) and over slightly smaller ranges: ascent - 197 to 236 ft and descent - 197 to 246 ft.

freeheeler · 26 Oct 2019, 06:52

@silentvoyager
and the question is: will Suunto be able to improve this?

Nick Vlahandreas · 2 Mar 2020, 10:10

I’ve just posted about a similar issue. My issue kicked in around the same time as these posts and still we have had no response from Suunto on a fix.

Bulkan · 2 Mar 2020, 11:04

@Nick-Vlahandreas said in Problem of cumulative elevation gain:

I’ve just posted about a similar issue. My issue kicked in around the same time as these posts and still we have had no response from Suunto on a fix.

Where did you post it? Did you get any response from Suunto?

If you posted here I see your are getting responses and help. And you had one watch replacement.

Please, let’s write about truth and don’t let the emotions write thing like: still we have had no response from Suunto on a fix.

isazi · 14 Jan 2021, 17:26

Mind sharing an altitude graphs? Can you see lots of little spikes? Is the altitude right or wrong?

freeheeler · 14 Jan 2021, 18:05

@isazi
mind merging this topic https://forum.suunto.com/topic/3388/problem-of-cumulative-elevation-gain?_=1610647206541

@Andrea-Lo-Manto
you’re not alone, but what you see seems to be a lot!
When the skilled guys here see your alti graph they can make a tendency diagnosis.
Common issues are blocked baro holes, e.g. by rainjacket, tight watch wearing style etc…

isazi · 14 Jan 2021, 18:11

@freeheeler there is no merge button in the forum. If the OP wants we can lock this one and keep discussing in the other one.

freeheeler · 14 Jan 2021, 18:14

@isazi
ah really? I thought few of us have a magic button to merge similar topics sorry, ignore my comment

Daretodream · 30 Dec 2021, 07:56

@freeheeler I am experiencing some issues with elevation gain in general as well, especially since running with a Stryd footpod.
Issues I am experiencing:

Watch showing way to much elevation gain while Stryd shows more realistic elevation gain (e.g. on really flat course watch says 230m up/down, stryd says 20m up/down and TP elevation correction shows 15m)
Watch shows 0 elevation gain while Stryd shows more realistic elevation gain on 1min hill intervals (e.g. watch says 0m up/down, stryd says 363m up/down and TP elevation correction shows 262m up/down)

The values in TP before elevation correction are the values from my watch. I am not into a precision of like 1-2m elevation gain however a realistic elevation reading would be very helpful. Could you explain where the baro holes on the watch are, then I can check those. Any other ideas? Could coupling a footpod to the baro cause such a major difference?

isazi · 30 Dec 2021, 08:19

@daretodream said in Problem of cumulative elevation gain:

Could coupling a footpod to the baro cause such a major difference?

No, the pod is not the cause of the issue (I run with it every time).

Brad_Olwin · 30 Dec 2021, 14:19

@daretodream It is possible that the sensor hole is obstructed. Or, if there was high wind and the wind hits the sensor hole this can happen.