Suunto, what the hell with your data recording?

[teo's]

Hello everyone, I’d like to share with you the huge error on total altitude that my brand new Suunto Race made today. This morning I made an excursion on a mountain 1 hour far from home. Things appearently went fine with Race, but when I came back home and had a look to the report on Suunto App, one data made me going crazy: the altitude. The app, just like you can check on attached files, talks about 3292 meters of total positive difference in height. This would be and astonishing result for me (in fact also the real one made me really happy, but this is not the topic of discussion), but unfortunately is a fake number. What I expected is a number around the half, considered that I started my hike from about 1000 meters and reached the top around 2500 meters. Add that I made in between another peak, add some up & down, and my expected numbers where between 1550 and 1650 meters. So a complete mistake for the Race. Also because it was a fully sunny day from beginning to end, and the path, except maybe for about 50-100 meters (on more than 17 kilometers of excursion) of undergrouth, was completely on open sky, so ideal conditions for a sportwatch to record a very accurate track.

Seems like a bug or something else, also because the altitude graphic of the excursion, looks like real, and so is the total distance of 17.2 kms. Seems like it considered “ascent” the sum of ascent and descent, but the “descent” has her own value of 3287 mts.

For completion of information I add that the Race was updated to the latest firmware as soon as it was available, and that the smartwatch was sinchronized with the app just before the excursion. I also add the .fit file of the day.

It would be great hear and explanation of this from a Suunto technician, but if someone of you Race users know what happen… I’m here to listen to you! Thanks!!

File .fit

[surfboomerang]

@teo-s How do you wear the watch? Is it possible that the holes for the barometer were blocked?
Or did the watch caught a lot of wind?

[teo's]

@surfboomerang Hi, thanks for your reply! I wear the watch always on my left arm. I don’t think that the baro holes were covered, I stopped my gloves just before the Race. About wind, i got several gusts of wind, some even quite enough strong, but something occasionali, definitely not continuous.

However, what I don’t understand is how the total is more than 3200 mts, while the data on graphic profile are good enough. I mean, seems like the watch in fact recorded the tight altitude step by step, but after all was unable to make the sum of them…

[surfboomerang]

@teo-s Strange, I just ran your file through Quantified-self.io. It also shows an elevation graph from 1000-2500m. However, when I zoom in, I see a lot of elevation wobbles. As far as I remember, there is a wobble threshold of around 3m, but your wobbles are bigger. Maybe that’s the reason why the ascend and descend values are much more.

[GiPFELKiND]

@surfboomerang how should wind change the values? Think only a barometer change (high barometer or low barometer change) will change the values? But only wind?

[Łukasz Szmigiel]

@GiPFELKiND wind can influence the baro sensor a lot, but it has to be either a strong wind or you have to be moving faster than walking / running.

[surfboomerang]

@GiPFELKiND Wind and water are two reasons why altitude is disabled for windsurfing. You should see my altitude graphs on windsurf sessions in the past.
If I only could use those ascend values for Suunto Vertical week…

[Dimitrios Kanellopoulos]

@teo-s I looked at your file. It looks like there was something on top of the pressure sensor you can see dips all over the chart

• Rain?
• Watch got rain then got under the jacket?
• Dirty sensor -> Sampoo cloged etc?
• Wind? I would doubt that though as the issue looks a little consistent.
• Humidity ? ?

[teo's]

@Dimitrios-Kanellopoulos Hi thanks for your reply! I exclude absolutely rain, as I said on my opening post it was a fully sunny day all day long. I exclude also humidity, because sun and partial wind made the ambience quite enough dry. On your list the only thing that effectively happened was wind, but again, wind never blew continuously, and probably 3-4 times strong on a 8 hour trekking. To be clear, It was a typical wind day on a high quote mountain, I’m really surprised if wind could be the cause of this numbers, because it means that potentially almost every trekking may end with a completely wrong height difference number.

However, one thing that I forgot to say yesterday was the fact that, to avoid the typical fake extra lenght due to continuous positioning fix when stopped, I paused the track record three times, and started to record again as soon as I came back to walk. I don’t know if somehow this thing may caused the problem. That said, I usually do pause the track record on long stops and never had the altitude problem.

[Dimitrios Kanellopoulos]

@teo-s give it a run on a flat and let’s see the profile. Or walk.

I definitely don’t see this as sw issue.

[Mff73]

@teo-s
you forgot “dirty sensor” from the list of potential culprits.
It is worth having a check on this.

[teo's]

@Mff73 Honestly I really doubt this can be the reason of the problem. Exactly tò avoid this problem, I wear my Race only on weekend, while during the other working days of the week I use my Fenix. Moreover, this was just the second trekking I had the chance to use the Race since I bought the watch, about 1 month and half ago. Given this, I’d be very surprised if all of this was on dust…

[teo's]

@Dimitrios-Kanellopoulos Ok, I’ll try to use it as soon as I can.