Suunto 9 FusedAlti not remembered after activity

surfboomerang

I noticed today that the altitude before the activity was too high (+32m). During the activity the altitude was change to the right altitude (-1m), but I noticed that right after I ended the activity the altitude was instantly adjusted to the previous (wrong) altitude.

Anyone else experienced this?

sartoric

FusedAlti works only during the activity afaik, since gps isn’t active on normal use.
As soon as you start the activity fusedalti starts the auto-calibration

This post is deleted!

sartoric

@surfboomerang
What happen if you manually run alti auto-calibration ?

surfboomerang

No sorry, no high buildings

If I activate fusedalti while not in an activity it sets the altitude correctly after a short while as it supposed to do.
I thought that the corrected altitude in an activity would also be the altitude once the activity ended. So I never calibrated the altitude because I assumed that it would do that during activities.

sartoric

@surfboomerang
Well, altitude in normal mode is based on barometer measurements so it can be affected by weather changes and the altitude value you’ve set on watch.

surfboomerang

Normally I would agree, but not this time. It changed so rapidly after I ended an activity. And to almost the same value right before the start of the activity.

The graph shows a time scale of 2 hrs. My activity was 1:40 so it changed within 10 minutes after the activity.

surfboomerang

I rebooted the watch and did a run today. Before the run the altitude was way too high. After a couple of minutes into the run I noticed that the altitude has been corrected to the right altitude. After I stopped the activity it remained the same altitude this time.

So it looks like a one time error…

Brad_Olwin

I think this is normal behavior. It does not happen to me as I live at 1600m or 5200 ft and routinely see changes of 100-200 ft primarily due to changes in air pressure. Most of my exercises involve changes of 1000 ft or 300m in altitude. FusedAlti when working will adjust altitude to the correct by using aided GPS. If the air pressure during your exercise changes, that will be reflected in a change in altitude when you stop the exercise…not surprising. If you alitude changes are small, I expect this is more challenging for the watch.

Hopefully this is a better thread (I’ve just posted a comment in another one). Here is good example that demonstrates that FusedAlti adjustment isn’t remembered after ending an activity. The following two activities were recorded about 5 minutes one after another. As you can see FusedAlti kicked in both activities and made nearly the same adjustment:

Brad_Olwin

@silentvoyager Not clear on your post, what is not remembered? I see two separate graphs. Is there no change in your altitude? What happened to air pressure during this time?

surfboomerang

@Brad_Olwin what @silentvoyager is saying is that he sees the fused altitude working in the first graph within a few minutes. The first activity ends at an altitude of around 339m.

He starts the second activity 5 minutes later with an altitude of 258m. Such a huge difference can’t be from air pressure change in such a short time.

After a few minutes he sees the fused altitude working again because the altitude is corrected to 344m (almost identical as the end altitude of the first activity).

You would suspect that after the ending the first activity the altitude will stay at around 339m until he starts the second activity. If the second activity starts days after the first I can imagine the altitude has drifted off because of air pressure changes, bit not after 5 minutes.

@silentvoyager correct me if I understood your post wrong.

Brad_Olwin

@surfboomerang said in Suunto 9 FusedAlti not remembered after activity:

@Brad_Olwin what @silentvoyager is saying is that he sees the fused altitude working in the first graph within a few minutes. The first activity ends at an altitude of around 339m.

He starts the second activity 5 minutes later with an altitude of 258m. Such a huge difference can’t be from air pressure change in such a short time.

After a few minutes he sees the fused altitude working again because the altitude is corrected to 344m (almost identical as the end altitude of the first activity).

You would suspect that after the ending the first activity the altitude will stay at around 339m until he starts the second activity. If the second activity starts days after the first I can imagine the altitude has drifted off because of air pressure changes, bit not after 5 minutes.

@silentvoyager correct me if I understood your post wrong.

The first activity ends at about ~214 and the second starts very, very close to that once Fused Altitude has initiated…are you saying the second should start at 215? Mine tends to remember as I can check altitude.

Mff73

@Brad_Olwin
I think the first is your second and the second your first.
But maybe wrong.

@Brad_Olwin The second one started 5 minutes after finishing the first one. The change in altitude between the two runs was insignificant. You can see a significant altitude adjustment at the beginning of the second run, which doesn’t make much sense to me.

@Brad_Olwin, No 214 ft is where I started the first activity and where I returned to at the end of the second activity. Basically my run was interrupted because I met someone and stopped the run, but then decided to record the rest of it.

freeheeler

I’d like to roll up this ancient topic if I’m allowed to…
but with a somehow different basis of the question to you folks.
Did you ever notice that all your start altitudes that you start from a known point differ by several meters? My frequent starting alti is on 424m.
My activities sometimes show 404m on the graph up to 449m. But usually around 416m, hence 8m too low.

I know that FusedAlti kicks in after something like 15minutes but I remember that it changes the graph backwards in order to not only correct the altitude but also correct a potentially wrong start altitude, am I wrong?

What is your experience?

freeheeler

…and while I’m already asking…
I went for a short ride along the lake (which is supposed to be a flat track) and I went to a shop (5th floor) while I paused my activity and later I found the following on the alti graph recording… I’ve restarted the activity exactly where I’ve stopped it some minutes before.

Dimitrios Kanellopoulos

@TELE-HO temperature influence. That has not Todo with correction. If you stay inside it will get wrong gps altitude and temperature will be increasing or falling changing the altitude. That is why 20meters chnaged

Dimitrios Kanellopoulos

@TELE-HO fused alti does not work only in the first 15 minutes. This is chnages quite some time ago. It will try many times and additionally constantly correcting the altitude