For s9p and s9b

[Brad_Olwin]

@outtatime said in For s9p and s9b:

Maybe not all the watches fault, but drive across town and come back home the baro will be off about 50 feet.

I drive ~ 25 miles to and from work where the actual altitude difference is about 500 or 600 feet. My watch is typically within 100 feet of the actual altitude. Typically our weather is responsible for the change. Once I do an outside exercise the altitude is correct. I just let fused Alti do its job.

[A Former User]

@outtatime there was an interesting post (search the forum) about the matter. Long story short: FusedAlti is used, of course, inside an activity session and when you use the watch as watch, so there’s no need to manually set the altitude reference in both cases as suggested by the other people. Since then I’ve never manually corrected the altitude even if the weather is changing… and it is almost always spot on

[Tieutieu]

Interesting : I have an opposite behaviour to set up altitude on my S9B…I calibrate it always manually when I’m on an known reference altitude. I found the automatic calibration far too long and not as precise.
Derivation highly depend on weather changes. I live at 282m high. Doing some large car travel for work, I have often up to 40/50m derivation. When staying at home it never reach more than 20m.
I

[A Former User]

@Tieutieu said in For s9p and s9b:

Derivation highly depend on weather changes

sure but, at least on my S9P, as soon as I move altitude is being corrected

[Tieutieu]

@gi0vanni I also noticed that derivation on my wife’s S9P is far less important than on my S9B. Perhaps I missed a setting on my watch ?

[A Former User]

@Tieutieu said in For s9p and s9b:

Perhaps I missed a setting on my watch ?

I do not think so.
Just to be sure things work as intended try to manually set altitude to a crazy value. It should be corrected within ~15min by FusedAlti.

[freeheeler]

@Tieutieu
you can avoid this extra effort
FusedAlti will adjust after around 15minutes and overwrites your manual adjustment if necessary. you can try: set it 2’000m wrong, after 15min in activity (with satellites) it corrects altitude.
it works like a charm

[sartoric]

@freeheeler said in For s9p and s9b:

FusedAlti will adjust after around 15minutes and overwrites your manual adjustment

I’m not sure about this.
Maybe there’s something new in the latest firmware but afair, if you manually set the altitude before starting the activity, FA won’t kick in

[renton82]

@gi0vanni said in For s9p and s9b:

… FusedAlti is used, of course, inside an activity session and when you use the watch as watch, …

I don’t think FusedAlti works outside of an activity, maybe am i missed something?

[freeheeler]

@sartoric
no, that was until some years ago. you can manually adjust whenever you want… FusedAlti knows it always better

[outtatime]

Over a significant travel distance you could expect the baro to change. But as far as fusedalti, it working without gps might operate the same as just watch mode.

[outtatime]

@Tieutieu said in For s9p and s9b:

@gi0vanni I also noticed that derivation on my wife’s S9P is far less important than on my S9B. Perhaps I missed a setting on my watch ?

S9P apparently fixed some of the problems that S9B had.

[outtatime]

@freeheeler said in For s9p and s9b:

@outtatime
the reason could be various… assuming you just look at altitude in watch mode? or does this happen during an activity?

It looks like it can be off on the activity mode as well. So it’s not just baro. Gps has its own ellipsoid that it follows and is a rough estimate of altitude.