How is the altimeter?

Can anyone comment on the accuracy of the altimeter? On my 945 I notice that the altitude will creep steadily after I calibrate or after a run. For example, right now my altitude reads 341ft, actual should be 299ft. After my run yesterday the altimeter reading was 302ft so in the course of 24 hours it has drifted by almost 15%.

Top Replies

nmyeti over 5 years ago in reply to renton82 +2

The continuous calibration works pretty well against the dem map that is part of the topoactive north america map on my watch. Can't speak to any of the other DEM maps. Was up to 13,102 recently and the…
Former Member over 5 years ago +2 suggested

I also noticed this.yesterday I calibrated manually my 6s Pro. I used Google earth. My ground altitude is 54 m(177 feet) ASL. I sleep on a 2nd floor. The next day, perhaps after 28 hours my ground altitude…
tboooe over 5 years ago +1

Yes, during an activity the altitude seems accurate enough. I am seeing the drift after the activity ends. nmyeti can you please elaborate on the calibration with the Android GCM? If this is working for…

All Replies

0 Former Member over 5 years ago in reply to C.sco

C.sco said:
The change was gradual - meaning, that the DEM file thought he was at ground level, while the altimeter thought he was 10k feet above that

Something doesn't add up with this user's post. While it's true that DEM would assume he's at ground level and calibrate to that elevation, the altimeter wouldn't have shown 10K feet because the cabin is pressurized. I've taken many flights and it doesn't read that high.

0 javier1892 over 5 years ago in reply to Former Member

This is precisely why I always have autocalibration off during activity. In steep terrain it doesn't work well at all for me due to minor positional inaccuracies resulting in major altitude errors...

0 C.sco over 5 years ago in reply to Former Member

It was his personal aircraft (like a Cessna or something like that), not a commercial flight, it was not a pressurized-cabin aircraft.

0 Former Member over 5 years ago in reply to C.sco

Makes sense and I wasn't thinking outside the box. Lol. I feel like Jerry Seinfeld in the episode about the dermatologist saving lives. Too make matters worse, I was a paratrooper in the military with 73 jumps under my belt. Those aircraft weren't pressurized either. Don't know what I was thinking.