Series 6 Altimeter Discrepancies

[Cheefy]

Your elevation will be calculated by one of 2 ways.

By using the built in GPS chip (you will have to be outdoors for an accurate reading)
or by using the built in barometer (hopefully not both at the same time)

If the watch is using the built in barometer for elevation then your will get large errors of accuracy as pressure changes. The barometer is also used for workouts as it is very accurate for detecting small increases or decreases in height (going up stairs etc), no GPS signal is required. If however you are jogging and the weather starts getting worse( the pressure will drop) and you watch will assume your elevation has changed resulting in elevation errors.

As a very approximate guide: 1mb of pressure is equal to 10meters in height.
As pressure drops due to weather changes your watch will indicate an increase in height (and vice versa). This only happens if the watch is using the built in barometer for reference.

Disconnect your watch from your phone, go outside where there is a clear view of the sky, take an elevation reading (compare the my altitude app from the built in altimeter app). Do the same over the next day or 2 at the same point, if you are getting different readings, the watch will be using the barometer.


Either way you can disable the barometer via your phone, which in turn disables it in your watch.
I am thinking of buying a series 6 for the always on altimeter but not if it gets its readings via the barometer and if I disable the barometer will the always on altimeter still work?

I think we’re all agreed on what’s going on here but the watch was advertised with an all day altimeter which at the moment it may as well not have. This is a very advanced chip and it would be very easy for the “experts” to build in the right algorithms and facilitate calibration to get the altimeter readings usable. As it is, it simply cannot be relied on. Apple will have to sort this one out to save face. The right values are in there somewhere as the My Altitude is always correct. After getting ridiculous values for three days (from new) suddenly this morning the altimeter via the Apple Compass App was reading bang on 60 mtrs where I live. So I set the always on Altimeter and drove down to the beach where it read 3 mtrs - brilliant. I then set a walking activity on Strava, walked for an hour along the beach (same level) after which it was reading 259 mtrs. The Strava activity analysis had the correct elevation in all the way through 3 to 5 mtrs. So what changed there because the barometric pressure didnt - if anything it went up a bit not down. I’m sure this is fixable but on the chance that it is not there will an awful lot of returned AW 6’s.

 

[Cheefy]

i just checked my watches alti reading today and found it in the 'proper' range again.. i am confused.
The days before, it always showed 120 meters plus.

((pressure level is at about 993,5hpa around here)

Funny old thing my local barometric pressure (Dundee Scotland) went up to 992 mbar from 965 mbar and the Apple Compass App started reading correctly. Sadly a couple of hours later it was back up to 259 mtrs at sea level. The barometric pressure might have altered a wee bit but if anything it went up and it certainly didn’t change enough to go from 3 mtrs to 259 mtrs in one hour - it has been a calm sunny day.

 

[Cheefy]

I agree that there is error in the reported elevation when using the complication or compass app on the watch, directly related to barometric pressure changes based on weather over time, and that error is also saved in a workout in the activity app. But this error is only or mainly about displaying your absolute altitude as an initial position (ie how high above sea level you are at a given spot) and not about error in measuring your change in altitude during a workout. The always on altimeter of the S6 is significantly better at tracking elevation change than my previous S3. Tracking change in altitude is the purpose of an altimeter, so that part works fine; initial position is related to how you calibrate the altimeter, so that is the error here.

But: the apple watch does track elevation correctly and you can use and see the correct value, if you use a workout tracking app like Workoutdoors or Strava, or an altimeter app like Altimeter+ or UpHigh. Those apps can work independently on the watch without your phone and using WOD as an example, can display your correct altitude in real time in the app correctly. So the bug is that the apple watch complication is not showing the correct value for altitude, when if fact that data point exists and is available on the watch.

While the altimeter will at times calibrate and reset itself at night or at other times, I continue to believe that best way to force the watch to recalibrate the altimeter is to move it to a new location 5-10 miles away and/or up or down a significant hill (of say 300 feet/100 meters). I don't see that anyone else here has done this or said whether this works or does not work. But it works for me (it seems to reset on the return home, so it may continue the error on the trip out, but will reset at some point as it returns or after it returns the original position).

I’m sorry I have to disagree with some of this. Saying the all day altimeter is only there to indicate a change of elevation. I can’t imagine a Passenger Plane Pilot would be happy with that - there would be plane crashes all over the place. And that reasoning doesn’t explain why my altimeter today read correct first thing this morning and then went from 3 mtrs at sea level to 259 mtrs still at sea level an hour later. There is no way that is working correctly let alone useful. What possible purpose could that information serve. It was advertised as an all day altimeter and that is what it should be.

 

[McKain]

I started with the series 4 Apple Watch, specifically for the altimeter while hiking in the mountains. I have no need for any of the extra sensors that come with the watch, so while hiking I always use the watch independently of the phone. Watch in airplane mode and phone switched off. I have navigated for almost 3 years now using this method and the Viewranger map installed on the watch for the area I will be hiking. The watch has always shown to be very accurate, + or - 10 meter accuracy, so if a mountain is 1000meters high the watch will show a range from 990-1010 when I get to the summit, not bad for something on your wrist! and as accurate as my standalone GPS unit. This method only uses GPS (orbiting satellites), no need for any internal sensors are required.

The barometer inside your watch (and phone) can measure small increases in pressure due to atmospheric changes, this can be used to determine stairs climbed and for other fitness uses as well as a form of altitude. If there is a change in pressure the watch does not know if you have increased your altitude or the pressure is dropping naturally. This is why barometric altimeters always need to be set all the time. The barometer has nothing to do with GPS.

Not having a Series 6 I cannot comment on the always on altimeter, but for a constant connection to GPS (orbiting satellites) you would have to be outside with clear view of the sky otherwise the watch would be constantly searching for a signal which would drain the battery in no time.
I can only assume the always on altimeter is using the barometric sensor which (while connected to wifi or cellular can give you an approximate altitude by either your wifi or by pinging nearby cellular towers. If you then leave your house and go for a walk, I'm assuming its still pinging wifi/ cellular towers otherwise, an always on GPS connection would destroy battery life.
Does the always on altimeter let you input an altitude if your know the height of your location?

If this is indeed the case I would just use the compass app for an accurate GPS altitude reading (while outdoors!), unless this app has been updated to mirror the always on app. I need a Series 6 to find out!

For use in the mountains with no cellular service the GPS in the apple watch I have found to be as accurate as my Garmin.

 

[StumpyBloke]

If this is indeed the case I would just use the compass app for an accurate GPS altitude reading (while outdoors!), unless this app has been updated to mirror the always on app. I need a Series 6 to find out!

The compass app does show the incorrect readings. The whole thing is crap!

 

[Cheefy]

I started with the series 4 Apple Watch, specifically for the altimeter while hiking in the mountains. I have no need for any of the extra sensors that come with the watch, so while hiking I always use the watch independently of the phone. Watch in airplane mode and phone switched off. I have navigated for almost 3 years now using this method and the Viewranger map installed on the watch for the area I will be hiking. The watch has always shown to be very accurate, + or - 10 meter accuracy, so if a mountain is 1000meters high the watch will show a range from 990-1010 when I get to the summit, not bad for something on your wrist! and as accurate as my standalone GPS unit. This method only uses GPS (orbiting satellites), no need for any internal sensors are required.

The barometer inside your watch (and phone) can measure small increases in pressure due to atmospheric changes, this can be used to determine stairs climbed and for other fitness uses as well as a form of altitude. If there is a change in pressure the watch does not know if you have increased your altitude or the pressure is dropping naturally. This is why barometric altimeters always need to be set all the time. The barometer has nothing to do with GPS.

Not having a Series 6 I cannot comment on the always on altimeter, but for a constant connection to GPS (orbiting satellites) you would have to be outside with clear view of the sky otherwise the watch would be constantly searching for a signal which would drain the battery in no time.
I can only assume the always on altimeter is using the barometric sensor which (while connected to wifi or cellular can give you an approximate altitude by either your wifi or by pinging nearby cellular towers. If you then leave your house and go for a walk, I'm assuming its still pinging wifi/ cellular towers otherwise, an always on GPS connection would destroy battery life.
Does the always on altimeter let you input an altitude if your know the height of your location?

If this is indeed the case I would just use the compass app for an accurate GPS altitude reading (while outdoors!), unless this app has been updated to mirror the always on app. I need a Series 6 to find out!

For use in the mountains with no cellular service the GPS in the apple watch I have found to be as accurate as my Garmin.

No the watch doesn’t allow you to input an elevation figure based on GPS coordinates. My AW 6 varies by 100’s of mtrs whether I’m ascending or descending or walking on the flat by amounts that have no accuracy whatsoever. Using a third party App the elevation indicated is perfectly usable and appears correct. Presumably the third party app is just using the GPS. It makes no difference whether I use it with my IPhone or without. It is hopelessly unreliable.

 

[Cheefy]

The compass app does show the incorrect readings. The whole thing is crap!

Agreed ?.

 

[michaelb5000]

I’m sorry I have to disagree with some of this. Saying the all day altimeter is only there to indicate a change of elevation. I can’t imagine a Passenger Plane Pilot would be happy with that - there would be plane crashes all over the place. And that reasoning doesn’t explain why my altimeter today read correct first thing this morning and then went from 3 mtrs at sea level to 259 mtrs still at sea level an hour later. There is no way that is working correctly let alone useful. What possible purpose could that information serve. It was advertised as an all day altimeter and that is what it should be.

Ok, yes, I understand your point, and some of this is semantics. I don't fly planes, but I assume they set the altimeter to an exact known reference, ie the altitude of the airport, before take off. If they made a mistake and set the reference elevation to be off by 1000m, the onboard altimeter would "correctly" report the change in elevation throughout the flight but be off by 1000m. An altimeter does not know your initial position. So the error in the apple watch is in reporting the "initial" position of you as the user, which mostly relates to how that is being calibrated, probably by GPS. But as I said above, the Watch actually does know your correct position and elevation, because other apps can give you that info, so if you really want to see your elevation, use Workoutdoors when walking or hiking or biking.

 

[McKain]

No the watch doesn’t allow you to input an elevation figure based on GPS coordinates.

I was curious if the always on altimeter lets you specify an altitude, not GPS coordinates.
If my house is 100 meters above sea level, can I then set the always on altimeter app to 100 meters while I am at home
Or is there a way to calibrate the barometer and tell it I am currently at this or that altitude?

This is how old watches from the 80's and 90's worked out altitude (from barometric readings)

 

[agerly]

Same problem here from few days after a huge decreasing in atmosferic pressure I have +200m reading from complication in AW6. What I really don't get is:
-Does the aw6 have a barometer inside? Yes (of course)
-does the aw6 have a gps internally separated from the iphone? Yes otherwise any external activity would be useless without the phone

Now if the pressure drops i expect that aw6 reads the gps altitude and associate that altitude to the barometer readings, it's very basic...it means automatic calibration, necessary because it's normal that at sea level you don't have 1013 mbar 365 days per year. After the calibration, which by the the way can be done also using Internet connection if avaliable and dem data, the barometer will be very accurate. It looks like there is no such BASIC tuning of the altimeter neither automatic nor manual which leaves us to....stupid numbers.

What a disappointing piece of useless software....

 

[Cheefy]

Ok, yes, I understand your point, and some of this is semantics. I don't fly planes, but I assume they set the altimeter to an exact known reference, ie the altitude of the airport, before take off. If they made a mistake and set the reference elevation to be off by 1000m, the onboard altimeter would "correctly" report the change in elevation throughout the flight but be off by 1000m. An altimeter does not know your initial position. So the error in the apple watch is in reporting the "initial" position of you as the user, which mostly relates to how that is being calibrated, probably by GPS. But as I said above, the Watch actually does know your correct position and elevation, because other apps can give you that info, so if you really want to see your elevation, use Workoutdoors when walking or hiking or biking.

My reference to planes was that if the altimeter on board (not the pilots watch) varied by wildly random amounts as my watch is doing then it wouldn’t be much use to the pilots. It may not be happening to everybody’s AW 6 but it’s happening to a lot. The random jumps, sometimes by 100’s of mtrs do not represent any conceivable useful information.

 

[michaelb5000]

No the watch doesn’t allow you to input an elevation figure based on GPS coordinates. My AW 6 varies by 100’s of mtrs whether I’m ascending or descending or walking on the flat by amounts that have no accuracy whatsoever. Using a third party App the elevation indicated is perfectly usable and appears correct. Presumably the third party app is just using the GPS. It makes no difference whether I use it with my IPhone or without. It is hopelessly unreliable.

I am virtually certain that apps like Workoutdoors and altimeter apps like UpHigh do not "just use" GPS. they are capable of tracking elevation using the altimeter on the watch. This was true before the S6, so my S3 did this as well, but the S6 is significantly better, a major upgrade, and so is not crap at all.

I do this every day and have for years: I go up and down a steep short hill. This is much like going up and down several flights of stairs (3-4 flights to be exact), so you can try this too. A GPS is inaccurate enough that it does not know if you are at the bottom of the hill/stairs or at the top or going in between. So if you just sit at the top of steep hill/stairs, your GPS vertical position can bounce around by more than the entire hill, as the GPS randomly moves around in its circle of position error. But with the altimeter, it doesn't matter if the watch reports your starting position at the bottom of the hill as 500 or 550, because the altimeter on the S6 will correctly determine the top of the hill when you get there as 550 or 600 respectively; and the bottom again as 500 or 550. You can repeat this 10x and see the altimeter correctly track 50 +/- up and down repeatedly. Workoutdoors records an elevation track in a graph, so if you do your 10x hill climbs and record that in WOD, after the workout you can look at that track on the phone and see that the watch correctly recorded 10 hill climbs of 50 and that the bottoms and the tops of that hill were all very close to each other on each repeat.

 

[Cheefy]

I was curious if the always on altimeter lets you specify an altitude, not GPS coordinates.
If my house is 100 meters above sea level, can I then set the always on altimeter app to 100 meters while I am at home
Or is there a way to calibrate the barometer and tell it I am currently at this or that altitude?

This is how old watches from the 80's and 90's worked out altitude (from barometric readings)

Unfortunately not.

 

[agerly]

I was curious if the always on altimeter lets you specify an altitude, not GPS coordinates.
If my house is 100 meters above sea level, can I then set the always on altimeter app to 100 meters while I am at home
Or is there a way to calibrate the barometer and tell it I am currently at this or that altitude?

This is how old watches from the 80's and 90's worked out altitude (from barometric readings)

No you cannot calibrate manually

 

[Cheefy]

I am virtually certain that apps like Workoutdoors and altimeter apps like UpHigh do not "just use" GPS. they are capable of tracking elevation using the altimeter on the watch. This was true before the S6, so my S3 did this as well, but the S6 is significantly better, a major upgrade, and so is not crap at all.

I do this every day and have for years: I go up and down a steep short hill. This is much like going up and down several flights of stairs (3-4 flights to be exact), so you can try this too. A GPS is inaccurate enough that it does not know if you are at the bottom of the hill/stairs or at the top or going in between. So if you just sit at the top of steep hill/stairs, your GPS vertical position can bounce around by more than the entire hill, as the GPS randomly moves around in its circle of position error. But with the altimeter, it doesn't matter if the watch reports your starting position at the bottom of the hill as 500 or 550, because the altimeter on the S6 will correctly determine the top of the hill when you get there as 550 or 600 respectively; and the bottom again as 500 or 550. You can repeat this 10x and see the altimeter correctly track 50 +/- up and down repeatedly. Workoutdoors records an elevation track in a graph, so if you do your 10x hill climbs and record that in WOD, after the workout you can look at that track on the phone and see that the watch correctly recorded 10 hill climbs of 50 and that the bottoms and the tops of that hill were all very close to each other on each repeat.

The same Compass App on my IPhone App works perfectly indicating correct altitude all the time. I don’t have to walk up and down stairs or mess around with it all. It just works.

 

[StumpyBloke]

It may not be happening to everybody’s AW 6 but it’s happening to a lot.

I genuinely believe it’s happening on all S6, it’s just many/most won’t use the feature.

It’s just an absolutely piss-poor implementation by Apple.

 

[McKain]

Looks as if the always on altimeter app is getting its elevation data from wifi/cellular then using the barometric sensor in the watch to adjust the elevation until it takes its next reading over wifi/cellular. This would not be accurate, but its just a hunch.

Can anyone with a series 6 disable fitness on their watch (via the phone) and see if the always on altimeter still works?

 

[agerly]

Why if I disable the Gps on the iPhone, compass is not getting any coordinate? And other apps like my altitude not working? I thought that aw6 had its own Gps...confused

 

[McKain]

Why if I disable the Gps on the iPhone, compass is not getting any coordinate? And other apps like my altitude not working? I thought that aw6 had its own Gps...confused

There is no setting on the phone or watch to disable GPS

 

[agerly]

There is no setting on the phone or watch to disable GPS

Yes there is: privacy settings - localisation. You can just google it

 

[McKain]

Yes there is: privacy settings - localisation. You can just google it

Never noticed that before, thanks!

 

[Cheefy]

I genuinely believe it’s happening on all S6, it’s just many/most won’t use the feature.

It’s just an absolutely piss-poor implementation by Apple.

Tonight while my AW 6 Compass App was saying my elevation was 308 mtrs I went out and did a quick walk using the Apple Workout App without my phone on me. When I got back I imported the Apple Workout to Strava and guess what my elevation was correct - varying between 60 mtrs at my house (correct) up to 75 mtrs whilst out walking - also correct. The more I/we go into this more peculiarities seem to surface. So the watches own Workout App had the correct elevation when exported to Strava but at the same time AW Compass App was telling me I was over 300 mtrs elevation. It would seem, more and more that the real problem is just the elevation value that we are seeing on the Compass App. The correct figure is in the watch ..... somewhere. That’s enough for one day - I have a headache ?.

 

[zerozoneice]

I continue to believe that best way to force the watch to recalibrate the altimeter is to move it to a new location 5-10 miles away and/or up or down a significant hill (of say 300 feet/100 meters). I don't see that anyone else here has done this or said whether this works or does not work.

and who in the right mind do you expect to do that on a regular basis??????

 

[zerozoneice]

I just did another outdoor walk exercise, but this time took the phone with me. I enabled Airplane Mode on the watch and disabled BT on the phone, just to make sure. Guess what: perfect gps track, perfect elevation, speed, pace...the works.

Got back to the car, disabled airplane mode and re-enabled BT on phone. Workout sync-ed perfectly, map is visible.
So for me, the resolution was to reset fitness calibration data and do my workouts without having the watch connected to the phone.

During the walk i noticed that the elevation readings were staying constant or at least within normal range. When i used to walk with my phone connected, most of the time i got weird elevation readings like 83m and the next minute -20m or some ****. Not reliable at all

 

[StumpyBloke]

Tonight while my AW 6 Compass App was saying my elevation was 308 mtrs I went out and did a quick walk using the Apple Workout App without my phone on me. When I got back I imported the Apple Workout to Strava and guess what my elevation was correct - varying between 60 mtrs at my house (correct) up to 75 mtrs whilst out walking - also correct. The more I/we go into this more peculiarities seem to surface. So the watches own Workout App had the correct elevation when exported to Strava but at the same time AW Compass App was telling me I was over 300 mtrs elevation. It would seem, more and more that the real problem is just the elevation value that we are seeing on the Compass App. The correct figure is in the watch ..... somewhere. That’s enough for one day - I have a headache .

Thanks for your testing. Don’t blame you for leaving it for now. I am as well. I’ve sent Apple the link to this thread and hopefully I’ll get a reply soon.