Spring - hiking - trekking - altitude

[Egika]

@Piotr-Grygiel just use the watch.
The FusedAlti algorithm will start sampling GPS altitude data and align those with the barometric sensor input.
Then as isazi said, after like 12-15mins, the GPS altitude information is usually good enough to adjust the altimeter.
No need to wait for this - it’s working in the background during the activity and does its magic unnoticed

[sartoric]

@Piotr-Grygiel
you’re missing a detail in isazi reply

and then applies the correction back to the start.

[Piotr Grygiel]

@sartoric In difficult terrain, forest it works poorly.

[sartoric]

@Piotr-Grygiel said in Spring - hiking - trekking - altitude:

@sartoric In difficult terrain, forest it works poorly.

what ?

[freeheeler]

@sartoric
I also have a different observation and opinion, but I am not there, so I can not contradict

[el2thek]

@Piotr-Grygiel Do you have an example?

[Brad_Olwin]

@Piotr-Grygiel I don’t find that to be the case. I never adjust the altitude on my watch. I let FusedAlti do its work.

[Piotr Grygiel]

@el2thek The same place 204-238 m

[el2thek]

@Piotr-Grygiel how is the gps? Would assume that is also somewhat off then.

[SuperFlo75]

Do you use the performance mode? AFAIK fused alti is not working in the endurance mode…

[deserthike20]

It’s been mentioned in these before in these forums that manually calibrating the altimeter prior to starting an activity effectively inhibits Fused Alti for that activity. So you may inadvertently be affecting the accuracy by manually entering the starting altitude.

Personally, I never calibrate the altimeter no matter how far off it is and just let it do its magic during the first 15 or so minutes of the activity.

I’ve never read how long before an activity this applies……

[freeheeler]

@deserthike20
it used to be 15min before activity afair but seems not to be valid anymore.
I did a test recently with manual adjustment, then immediate activity start and fusedalti did it’s job anyway

[Dimitrios Kanellopoulos]

@deserthike20 yes. Calibrating the altimeter before the activity with a -+15m real difference can influence the fused alti not to kick in for the first time.

What is said here is correct.

However keep in mind that fused alti always will kick in either continually and if the difference is more than 15m then also instantly if it has not happened before.

Also keep in mind that the reference altitude must be of the same format. MSL

[deserthike20]

@Dimitrios-Kanellopoulos @freeheeler

Thank you both for adding and clarifying how Fused Alti works.

[Piotr Grygiel]

An example of Fused Alti precision. Actual height from professional measurement on my wrist 218 m. In my S9PP it was 212 m.
S9PP sets the altitude at this point from 199 to 228 m. My yard is flat.

[Piotr Grygiel]

[vjakub]

@Dimitrios-Kanellopoulos How is the fused alti calibration process during an activity influenced when the watch is hidden under a winter jacket?

The reason I am asking is that I got superior results when I had my Race uncovered and then about 30m worse with the watch under the jacket.

[Egika]

@vjakub the calibration itself is not influenced. Just under the jacket there is a high probability that during movement air pressure building up periodically inside of the jacket. Thus generating noise in the barometric sensor signal.