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Altimeter issue

Anyone else getting false elevation reading on the 645M ?? Mine is consistently overestimating by 600ft.. any way of calibrating this???

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Former Member over 5 years ago +1 verified

Where can I find this?

You can find the manual calibration in Settings>Sensors & Accessories> Altimeter> Calibrate
maratonrunner over 4 years ago in reply to nsee +1

Can't see any difference and there wasn't any fixes for altimeter either. I have used workaround when altimeter stop working during the running activity. Another issue for me is "sawtooth" in the first…
syl20barRun over 4 years ago in reply to nsee +1

For me the altimeter is not working better with this new version.

Mais of the time it is under estimating the elevation by a smooth curve.

Sometime it is working but not able to understand why sometime…

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0 ge0kas over 5 years ago

As we all know every activity has GPS elevation too hidden in the fit file.
Is there a way to get rid of the barometric measurements AFTERWARDS?

0 pcraenme over 5 years ago

Ironically, I see the opposite with my 645.

After upgrading from a VAHR, the altitude graph of my 645 look much noisier, adding extra feet to elevation gains. I mean, there's no a lot of real-world roads with 1-2 meter high bumps all over the place. So, I would actually prefer more smoothing of high-frequency/low-amplitude details.

I am experiencing exactly the same. A flat road is displayed as a very bumpy road with 1-2m bumps. My previous VA HR was much smoother in this area.

0 dnicolaescu over 5 years ago

I am experiencing exactly the same. A flat road is displayed as a very bumpy road with 1-2m bumps. My previous VA HR was much smoother in this area.

What version are you on, pcraenme?

My original comment was for 4.0. I have to admit, that after upgrading to 4.1 I have never seen these noisy graphs again. On the other hand, I see oversmoothing of low-frequency data, just like the OP pointed out. So, it goes from on extremity to another...

I will try 4.2 today.

0 ge0kas over 5 years ago

Here is a direct comparison between barometric and GPS data.
FR645 elevation is indeed more polished.
Now I wish I could remove barometric data and replace with GPS data AFTERWARDSciq.forums.garmin.com/.../1430185.jpg

0 pcraenme over 5 years ago

What version are you on, pcraenme?

My original comment was for 4.0. I have to admit, that after upgrading to 4.1 I have never seen these noisy graphs again. On the other hand, I see oversmoothing of low-frequency data, just like the OP pointed out. So, it goes from on extremity to another...

I will try 4.2 today.

I am on 4.2.

0 nsee over 4 years ago

How is the elevation / altitude tracking like on the latest v5.90 firmware for FR645?

The only version that's been accurate for me has be v3.70 (https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-645-645-m/142041/altimeter-issue/832220#832220) and ever since v4.00-4.20 it's been poor again (https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-645-645-m/142041/altimeter-issue/842672#842672).

I had a replacement FR645 sent to be due to a screen issue, and it came with v3.70 (https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-645-645-m/156719/install-previous-version-of-ciq-apps---is-it-possible) so I've not updated the firmware.

I'm keen to upgrade to v5.90, but not if the elevation / altitude tracking is poor...

0 maratonrunner over 4 years ago in reply to nsee

Can't see any difference and there wasn't any fixes for altimeter either. I have used workaround when altimeter stop working during the running activity. Another issue for me is "sawtooth" in the first 1-3 km when running the race (like the marathon). For me both looks a software issue. Otherwise the altimeter works nicely.

0 syl20barRun over 4 years ago in reply to nsee

For me the altimeter is not working better with this new version.

Mais of the time it is under estimating the elevation by a smooth curve.

Sometime it is working but not able to understand why sometime it woks and sometimes not.

For information I am waiting more than 30 sec each time at it recommended.

For example, here after the smoothed altitudes which sound bad and the good one when it has worked.

These two graphicals have been done in a same course at two different time.

Bad Altimeter :

Good altimeter:

0 maratonrunner over 4 years ago in reply to syl20barRun

Does press stop and then start during activity make any difference? You can "monitor" the elevation during the activity to know when it stop working.

0 nsee over 4 years ago in reply to syl20barRun

Thanks - I will continue to stay on v3.70!