Altimeter recordings while running

[Mauerwegler]

@Mauerwegler said in Altimeter recordings while running:

I tried it yesterday with my Spartan Ultra:

• Offsetting the altitude by 60 m half an hour before training: altitude is correct in SA.

• Offsetting the altitude by 60 m directly before training: altitude is off by 60 m in SA.

So I guess the behavior depends on the watch generation?

I did another experiment yesterday, and now I am really confused:

• Commute to work with the bicycle without setting the altitude: everything as expected: altitude is quite accurate because I adjusted it the evening before because it had been off, see my quote above.

• Upon arrival at work I ended the training recording and maybe 15 minutes later I again increased the altitude by 60 m – I expected that the SSU would correct the offset during my commute home as it was offset more than 15 minutes before the commute home.

• In the evening I commuted home and in SA, the altitude is off by around 60 m although the manual altitude change was done in the morning, 9 hours before the ride home. The watch did not correct the altitude. Hm. I want to see the source code now.

Edit: I have a theory: after the end of a training the watch assumes that manual altitude changes are intended because the user arrived at a point with known altitude (summit, mountain hut, known location on map).

[isazi]

@Mauerwegler at this point, it would be more appropriate to leave this topic for the Vertical and move the Spartan thing in the right section of the forum. The software is different and so discussing them together does not make much sense.

[Clément Lavabre]

Hi, I think I have a similar thing with Race.
In activity, hiking, skiing, the watch has too much elevation gain. Particularly at low speed and especially when stationary

This has been happening since the December 18 update.
What do you think ? bug fixed soon? or sensor fault?

[Egika]

@Clément-Lavabre said in Altimeter recordings while running:

Hi, I think I have a similar thing with Race.
In activity, hiking, skiing, the watch has too much elevation gain. Particularly at low speed and especially when stationary

This has been happening since the December 18 update.
What do you think ? bug fixed soon? or sensor fault?

Neither fault nor bug.
What do you expect from this device?

I am seeing a change of around 2m in altitude over the time of 3 hours.
The accuracy of barometric altitude measurement lies within the range of 1m or so.
If this break during a skiing activity maybe you went indoors, there is also a temaperature change, and the baro sensor (while generally calibrated against the sensor temperature) might see some drift.

Conclusion: this very small altitude drift lies within the resolution of the sensor and maybe additionally affected by temperature change.

[Clément Lavabre]

@Egika Yes, the example is poorly chosen, the output is only 30 minutes.
But it is even more obvious on a long outing, where the normal altitude difference is around 700 m and the watch displays 1200 m.
And as soon as I stop, the altimeter goes back and forth.
You see it’s the alti measure during a break. All these variations are recorded in positive and negative gain.


And it is even more visible on the altimeter curve. As soon as I’m at low speed or stopped, everything changes.

And to compare, that’s a curve before update 2.30.38

No altitude variation during breaks, precise elevation change

[Egika]

@Clément-Lavabre I am not aware of any firmware related change with the December update, that would affect sensor data or the data interpretation in the watch.

can you rule out any other effect, like position of watch above/under clothes, dirt, etc. that usually affect the altitude measurement?

Cheers

[Clément Lavabre]

@Egika I’ve tried everything, with the sleeve on, without anything on, hanging on the bag strap, it doesn’t change anything, the results are bad.
I also tried soft-reset and hard-reset but it didn’t change anything.
Support does not provide any news by email.

On a daily basis I use the Race, but when active I have to take out my old 9 baro, it’s annoying.

Either it’s really a bug, or one of the sensors died at the same time as the update.

[Brad_Olwin]

@Clément-Lavabre This may be a sensor problem. Here is the output from my Vertical on my last SkiMo. The flat altitude is time during transition. I have no wobble.

[Clément Lavabre]

@Brad_Olwin This is exactly what I had before. I’m hesitating between waiting for a new update (is one planned?) or sending it for repair.

[isazi]

@Clément-Lavabre contact support, I doubt is the firmware considering that other people with the same firmware do not have the issue.