Track elevation wrongly recorded as near constant

Hi Michael,

could you please send the GPX for testing or at least a screenshot of the track elevation chart? Thanks

Hi

Thanks a lot for looking into this.

I have attached the gpx file below.

Here the altitude chart which initially I thought was inverted until I saw the scale:

Here a screenshot of the tracl:

Regards

M

Michael,

this is the only one track recorded by your new phone or all tracks show such an error? Locus Map processes elevation gain from the data it receives from your phone GPS. If the data are incorrect or contain huge deviations, then the resulting elevation gain is also incorrect. Locus Map, however, offers a few methods on how to limit these deviations. Open Locus settings > GPS&sensors:

- Location filter > select medium or heavier filter

- Google Services assisted location > turn it ON

- Altitude manager > settings tab > SRTM data - select "Optimize GPS values" or "Replace GPS values"

- Altitude manager > settings tab > Pressure sensor > turn ON (if available)

- Altitude manager > settings tab > Altitude filter - select medium or heavier filter

Try it , test it outdoors and let me know how it went.

Hi

Thank again for the help.

I actually had to check to see if I had used this phone before to record tracks and I did and the altitudes look correct.

On a note about the phone, it just updated to android 11 a few days before the recording.

Do you want me to set all those settings as indicated at one and the try it?

It will take some time before I get out again to do some walking, I will report back when I have tested this.

Regards

M

Hi Michael,

if you have Android 11, it is also necessary to get permission for Locus Map to access location when the app is running in the background, see https://docs.locusmap.app/doku.php?id=manual:faq:gps_lost_fix_android6#android_11.

ATB

Michal

Hi Michal

Thanks for that hint and the link. I checked the location permissions of the Locus Map app and they seem to be set correctly to "Allow all the time".

So I don't think it is a problem with the permissions.

By the way during the recording of the track I did open Locus Map a few times and checked my location on the map (I didn't look at the altitude).

Regards

M

Hi

I have done more testing. A couple of weeks ago I did another walk. Again the altitude did not change. So after a while I started playing with the settings. Nothing seemed to help, the altitude stayed fixed. So I decided to reset the settings to default which it couldn't finish due to me not being in mobile data reception (it seems to need that).

Once back I uninstalled LocusMap and reinstalled it.

I found a setting that records the GPS NMEA data which I enabled.

So this weekend I did another walk. I accidentally had the track recording set to driving, which is a shame.

The altitude changed to start with so I thought it might be working now. The tramp was essentially a climb up and then back down (about 1100m). After a while the altitude dropped back and stayed constant.

Note that there was mobile data coverage to start with and the later halve again. But even at the beginning the altitude was not right compare to the contours (maybe due to using driving mode?).

So after that I copied the NMEA log (~50MB) to my google drive, extracted the GGA sentences and plotted the altitude:

That looks about right.

So for some reason the GPS seems to provide the right data, but LocusMap does not interpret it correctly.

Any help would be much appreciated.

Regards

M

HI Michael,

we have registered more issues regarding the interpretation of the altitude data from GPS, regarding also the pressure sensor optimization - it is being processed. Nevertheless, your screenshots didn't make it through except the chard from NMEA, could you please send them once again? Thanks