My position over the ocean (altimeter)

[Kloakmunk]

My (altimeter) level over water meter is wierd. It goes down ten meters an hour and then up again what can I do? Or is everyone having this issue?

 

[B. Diddy]

Are you referring to your Galaxy Watch that you referred to in your other thread?

 

[Kloakmunk]

Yes, dont know how this site works get. So the thread was wrongly placed. But yeah it is

 

[B. Diddy]

Ok, I moved the thread to the Galaxy Watch forum for more specific traffic.

 

[Kloakmunk]

Thank you!

 

[Peter621022]

I'm no expert but I think the altitude is derived from the barometer pressure after consulting a database on the internet with the current barometer pressure for your location.
So changes in altitude could mean that the barometer pressure is changing.
I have no idea how big the variation of the barometer pressure is over water, but if you see that fluctuating as well then that could explain why the altitude as measured by the watch is fluctuating.

 

[B. Diddy]

If the watch does use barometric pressure, and if you're in a plane, then you're not actually measuring the outside pressure, you're measuring the cabin pressure (which is typically pressurized to 6000-8000 ft). If that's what your altimeter is reading, then you're probably reading the normal fluctuations of the cabin pressure.

 

[Kloakmunk]

I'm in my apartment, and every time I manually measure it it's the same again. But drops under time. The pressure should not drop in here. Unless the ventilation makes it. But then it's weird it's the same again if I manually do it again..
Thanks for answering guys

 

[Peter621022]

I'm in my apartment, and every time I manually measure it it's the same again. But drops under time. The pressure should not drop in here. Unless the ventilation makes it. But then it's weird it's the same again if I manually do it again..
Thanks for answering guys

The pressure in your apartment will fluctuate with the outside pressure unless you have an airtight apartment which I suspect you don't. Otherwise inside barometers wouldn't work.
That means that the pressure measured by your watch should drop and rise over time with changing weather. That's also the reason your watch needs to consult a database to translate the pressure into an altitude.

 

[Kloakmunk]

But I find it very weird it always the same if I manually measure it when it has dropped. It should update by it's own. Or is the manually measure from database and the drop time from the barometer?

 

[Peter621022]

I personally don't use this function on the watch, but here in Holland we have ever changing weather (certainly at this time of the year). I will keep an eye on the air pressure measurements in changing weather and let you know what I found.

 

[Kloakmunk]

Thanks. I like the feature but the barometer seems to work because it doesn't drop like altimeter does. And when I manually measure it comes back to my 42 meter. But then slowly goes down to 30 if I sont manually measure it. But the clock auto do it what I understand.. I dont know.. but thanks again

 

[Peter621022]

So I monitored both the air pressure measurement on my watch and the calculated altitude from it using a weather service as referece.
The air pressure goes up and down as expected with changing weather, but the value is 10-14hPa higher than the pressures as stated on a local weather service website.

The calculated altidude is lower because of the air pressure being measured too high, in my case it moves between -20m to -180m (the part of Holland where I live actually is below sea level, but not that much).

Someone else stated in another post that with quickly changing weather, the database that is being used by the watch as a reference can't keep up, which I think is plausible. This adds up to the inaccuracy of the altitude calculation.

So I guess you can't really use this feature on the watch if you need accurate pressure and/or altitude.
I guess what you can use it for is to predict showers or good weather coming up because of a rapid change in air pressure (which the watch does by default), but we have much better apps for that, also on the watch.