Do you think that the barometer/altimeter will be better then F3hr or even F5?
Or more likely, do you think, that the watch will callibrate it's altitude based on the topo maps? If so, the device will be very accurate. What is your opinion?
The f3 and f3HR currently calibrate via GPS, which is the same technique as would be used to "calibrate to the topo maps." That alone shouldn't make any difference, but there is certainly ample opportunity for improvement.
Hm, probably not; I think the OP's suggesting that the GPS location would be used to read an elevation from the map, which would be equivalent to elevation correction in Garmin Connect but done 'live'; the GPS-measured elevation wouldn't enter into it.
I don't like that idea much; doesn't deal well with bridges, doesn't deal well with routes along steep mountainsides. This route looked appalling with elevation correction originally; it was done with a FR 310xt, which is pretty accurate, but struggled enough with GPS inside the gorge that the route wandered back and forth across some very tight contour lines, so the 'corrected' elevation would have challenged a mountain goat.
ETA: actually, I think I've misunderstood the OP. Are you talking about calibrating at the start, or reading elevation continuously from the map?
There is certainly nothing preventing a manual calibration based on your actual position on a topo map - of course you would have to extrapolate your starting elevation between two contour lines - often 20 metres or more apart.
This is no different to what I do with a paper map - when I am at a known altitude (eg summit, trig beacon, water level) I manually calibrate if out by more than a few metres.
While I know there has been a lot of complaints about the F3HR barometer/altimeter my Fenix 3 has been pretty reliable for me. When I am trail running or biking I am typically not concerned about absolute altitude anyway - just height gained and height lost and on round trips these are always very close over the course of a few hours.
Yes, sorry, that was misleading.
I meant, that based on the GPS fix, maybe the watch will continuously calibrate the altimeter/barometer via the integrated topo maps (but not via GPS altitude, which IMO is very inaccurate). This way the "F3HR is fooled that you are climbing stairs " problem will be solved. But you made a good point about the bridges and steep mountainsides, but anyway, if you are walking for hours in a "not so steep" terrain you will always have an exact barometric reading. It won't be necessary to calibrate it manually via paper map or anything.
Sorry, I guess my engRish got really rusty :)
I pray that the 5x has fixed the altimeter issues. I had a Fenix 3 for a couple weeks but had to go back to my Ambit 3 because the Altimeter was always way off. My Ambit 3 peak was always right on the nose and I never calibrated it ever. The "fused alti" that they have is awesome, I can go from 500ft up to 6000ft and it would still be right on. I just hope that the 5x will be close to that.
Many, many years ago I had a watch with an altimeter built in. Calibration was a simple matter of finding the current barometric pressure for a point and putting that in (usually the nearest airport if I remember correctly). My height on the ground was then correct. If I didn't set the pressure, my height above ground might be wrong, but any movement up or down relative to that would not change. In short, irrespective of height above ground, corrected or otherwise, elevation gain and descent will remain relative to the start point.
If true height above sea level is vital then yes, you perhaps should have the ability to input current atmospheric pressure in order to calibrate it, otherwise I think it's largely irrelevant. What's more important is that you get a measure of your relative elevation gain and descent from your start point.
I've always found my Garmin good enough - except when the barometer 'blew up'. Yes there is some drift over the course of a long day, but overall, it's never been too much for me to be overly concerned.
Actually, DC Rainmaker gave an answer to that question in the comments to his F5 post:
"No, just based on GPS elevation/manual/etc…
However, it’s something they’ve look at/debated a lot. Essentially they noted that in theory this sounds good, but in testing/execution it almost ends up being more accurate to use the GPS elevation fix to calibrate. That’s because the definition in the contour lines isn’t always super accurate (less so than just using the GPS data which is often pretty good).
They’ve also considered some twists to this. For example they could save battery by turning off baro and snapping to grid after initial fix, but the battery life savings are so small by turning off baro, that for most people they’d be worse off accuracy wise with nearly negligible battery savings."
Regarding barometer calibration... at this point i think it's impossible to set correct pressure, now my fenix 5x is off about +1,5mb compared to my weather station (that is very accurate)... Have someone of you this kind of problem?
