Track elevation wrongly recorded as near constant

Michael Hagedorn shared this problem 34 days ago
Solved

I have the latest version of Locus Map Pro.

I recorded a track where we did a loop track up to summit and back down. The elevation changes is about 1000m. This is on a new Samsung Note20.

The problem is that the track elevations shown in the elevation graph are nearly constant and the height is around the starting elevation ~340m. The statistics page also shows 0 gained elevation. The rest of the track (2d locations) worked fine, so I get a nice outline of the track on the map.


I did export the track to GPX format and had a look at the elevation values and they are all constant.


Any idea of what might have gone wrong?

Might this be a problem with the Note20?

I have used track recording successfully on my previous phone.


Any help would be appreciated.

Regards

M

Comments (8)

photo
1

Hi Michael,

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

photo
1

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:

/dZ-BwNetY-tRIbNYu82ELNdyVoXlCFQu4FHnFT7egXbJ3zwZxiMe4UBBKymbm0UbN94zP3yDwqJv32GrQ9h7MC2BFc7Z6pGt9_YflEJB-bg-HP4K7Ra8xternftPjTx_y2CE-S2vIsP-As3NA_NwqEGiuVA6zMBPjcVHkL8YHROsk9P0OiWM9I2cGUEYnQOSmGArdz37pn0e1vnirUz-KrD2Njfbs15g2wNGD9nTuwBI_z8XAcuGH4HEy0LQOtnP-hNH_UseuTIzUi9XQutZTBMdTfuubcTt17k62UpyKYQE60efMWIswrMBavQzOIbRVtnZrOH4EQTvepn-YzAmNomv193fDZ24zMJbasZzyLijyTcLv3Q122pVrnIjZwhwCH3Uyar9R-tTZibHwmZxqV5hau1uTK1dmjvtbkMCCXhRILEOiWVEtESNkY0b9aLJfpWncugz7gjO8ansZRRzZWEqGtKxY1RsZ0hNYw0hkGbQRAAxtOv7-1MlWg_tSMIusGHgBvMAVKoqznCwt1PN-w1nqRlodvBtFQs7a6k8NSQRaHYro6IlsDI7gK42PYc09zj9r_0cTiCswp-zPsivIY2Z-zNzZ_OU9S3UHwQTX1RWZTq_GXKtvn0ywOqRvFLZUtsj8st6swuerLsdZPH-a5idSRPzDZa9dg2RsB015qUBkL1yjNwg-5yDceEja-Y=w946-h2028-no?authuser=0


Here a screenshot of the tracl:

/wBsD7Jr9Kkh2sy3jy0Vc8LcqyJ6PS1zbWMiWFXvQgJK9mrbd4uAcSipl_liWFxWF9IKJLZ-Y9fqvcw-L6kHJOCa-55a36OKYpC1V8in3jGpTizsF4JbZQSwYEecpNE-Td4DyBiGz_PUcc-YWEy5SHPGy1SGDEtOFPyGXst-GM3WVyu1fkL2pFAbqcXU2LNGo2aom4ZEfNVLFFWkquz3OCDSOpJL7GwKtPDO2bTPbW2Aa2HTC1GMOIhY74rKXpAXqjNAx-kMGxXfAEKMBuLy7GCoArO6S_tV4btib82oOqOgEbBuJ2IGnZD0E04RiGJUhfjycJ5LdNF7pSF-o2uGeou6U3QRCNquHd9TlbmTzBXIz1YSDJBxDCa93XYVqjUEQwzen8Uz90ABp4hGpJKEiFBRT8qbwgZgu9sPrKskdPdG7wIajeKaqmU8yARcg4dvBFdh4n6YFwn3gLlc5DCNeqEn7InusE1hp5EmTxS8UjMiworyII4-93QKNrW4lYjDhw5QMaQYHp90-OvfYPfOZJ4QhGSDp01z53tLuhIAA1_4yPbxh4zMjaYGlUaLKwMgfmM_IkD5qZ61Sw0JzzgqMXfdx_HRWyJTJmB0a2hvQ-XRKv3hTE9LfMJDhtTADFYax4EzvYGLC4W0MRiIkmiyFBJEiTqkbOYB18-UaULzfwRG-56KkP_n5KxNSMF93Ug8=w946-h2028-no?authuser=0

Regards

M

photo
1

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.

photo
1

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

photo
1

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

photo
1

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

photo
1

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?).

/9RyKXAhzx30UihdSbS18lVBr2n8A5jRmsdf_9OwfL9qBNJ9V1o3L8NOOySITP7irNXB0PAm1pam54coRXoj6mSXBkr2ThdY8BmFMxdndJ7_ok44wgq4CB8xZhJI8zZ8ZlfwN86fI9TMe_SzDjG5AovlXgYLkzk2oVw-k0pSCxuE5FarudlH2hu_NpbdgsfzHXyqTyrZPPbr00PjZjirw_qYPm9IcDTNR15NU2OH1GvOWUmM71TqMEwUv9TO_zZq-GO3eT5Z8w5UOiAK19viOf3d92eEMIJHX99-2iyIrs2bnirAf_gO3PF3FTEyz4lQg49hQmslLOTrGEMv7V2JYUQ06XlhXp_V6JUhG6WK3Lgqpqdnt8gWUikhSXHVga9-UEOzgH1y7wxD-NUen41L2IpeNioIC9D7Jl5xPAOrkuDvSHUw6qcWJKpq_XZydGZDSTxo-UtKPmMpUGRRBqI0PFw8z7Zy6EL2AUaRJybtVJGuIGiRVGjk3bKXxUkuxKbcM4eKUuDz0e5m6EqKBLgeSOFsIPIAZHSdN7Ql0tr2PL6V0qkIZS5WiQXXeSGfD6vj3kZnuIpNxc_dfjaOS3Iute44H_bhX6frfXmk8OCf6bGqxriHl9Ca_Ii2xJS2FS1hnFa2fn3xPY9Pid8V3tqQcQ5wdRhWnSvgYPaLlQIx40e_dF1gl0P6u7ZUNJextRmc=w946-h2028-no?authuser=0

/rviC9GL7my_3x1MlfGfSaxpxbEUW3USNtx0nHI6VhQYd8RDeZhBEa5-bfagdXVkryrRPTJatXz9hAHbo8Zd5sI_uZ5pv-Cvt0gpiCuZYjIOESjA62ZiASkyqiJQ9vfv_jsp0Vzudhd9uJB_sOPPl6aOwDmbajPPfyVM9H9LljNiV332WLiy_RD17DU6CVFV0CMZDNMCp7ty3yDtQYOPag0Zkp6yThxEziQXORcgMkXUjaydzI4X-EJGNYQdRaS3U5HRHn30hWV3Qx7ZIZloy11UthoNQYvEH4OddbqbHAEmng-FGb08t6krWTKV_IV95LWsWMFV3CrAu36XdTkrziQ61-gsSBy_kIRgi-Fo3_Kff_xyvTS11LIFss4jvvqpWjCfIvz0zmY_rX7KKldB0RbW8bXqp67sITikQaZMLQTR1qVXDQH5JZ4z38EdnpJV5ANPYo8COPbrFfZWRHUkWT_TO2vX_1IdYmPW_vNm01CWKkcDW0kScQCZMebyDUjFWgEKO6-B02q9ahvF5PJYGkd9ZyhLo1hADuqeeajpcMM8_M1uGDz3nNOIbTBwhcLJ-pX_FluZLU72m-b2Dq1VrE06oqA_kauIMw5mP7QTp2J1klQ1iDDJSXaYCz1DB3BHiyG_cTB2WnHqXulNgcVnY2ViXvxFrgSol1LfrmE7_FjpI0uNEK12r7VRV3gapQrE=w946-h2028-no?authuser=0


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

/e5083ab0bbb30c087f948a71f1a2b497


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

photo
1

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

photo
1

Hi Michal

I have added the screenshots again below.

Is there any workaround for the meantime?

Any other information you need?

Regards

M

/DmPk2bF9LmUeF9nZQG055RkSfV-ru8SK3L74i53x6zH3JzXaMW04_d6cRyD9Xy_hai-cSl3wt52qt6pLHfbLdDCgQSqEGDUGB9sGvZ6d8mZz2Xopv0JQeTyQyhNdM3dqqjj2PPU4LFAvnaZUtJ9tcm-qGMrEpP7MQbbuba1TNN-GbgaNVOC34LxKMoTogtvn77KosdBYw3mbbX2UX4d38tc4aJRlMjH1JbpPD1oZxqXeMMtmHt_Y-GM_HzydlG3AWqulOM_yuR15j7W8aoleHWikMGFG0xojgqkqaEjumuCVA0GQN5SsK8cdA-VKjf1uc3FlyzUpN5mZGjGVbSaaUMkgqo1ZwuEqGKlxZCxeR1bFsOgKgSnb5DyZBsMQZWkz5A1Cagzim1kJs9mGizfrJ2AhC3IqKH3OUmPN7W5FXz25be6UWkXxNq1cvBssnpviGyii2Ofrx-fuGoEeaxmsfqX6M6Wdw8nkVGUIuLKsZXjKMQnmXXask43mCtF1JNcD3QWI_wPir4-S7lQPhrcvM0RKDcwLSeX21HR-jG1jrUhY2V6Q5ao7qBMpbUA5XWAIymmubsG4v5Wi4DKdkeM0a7n3VJ2fCgPER98bKPFMfB4me2PQsNA2NjUBgWVDPJsrlF0iSqYN_ReS6zfdDH8FkvwMu50cUZDDwJx0Ah6k-7GipaeZpmGLoWIeCBMYMbc=w956-h2048-no?authuser=0

/_UyS5N3pCncNbuZcwCceg9ZvLQtOI1Ih24574TvibPieIZmKOTd17nV6_D4r-8TR5wzRZwaSryruXzmI72Ww1UcmiY3P21Nxkz_9M1Ifh_tuvsrscecNdIY8VZYVG44H0Ci8WNqntlNL6pEvONAznYtGQaxbXIcn4nJdGBKXegli_c4BcGCX9mHgXwMAl6l-xHtuhOx37TSFx9Q7YGpiYFxGdU5yzHJEOam16oMq_iWvGOoc0yZDjLC7OmFjxpFw5vS4dRTf9sDQpGxML3Cahnq_ChuErWcHHwtYwLy2MkrexGAwWzuTPSBaZS8DKa9MF_3Hy2brHvYgYsUSMrinDOOwRnLVawNuPnGwwVaeZxrY8juV4nkMrvKSl5GHFBqpvdSY7uWGxLpPs83nnAvUosXaKpiPmDG7nDJPUMQiXmMJBWlaXNijLYS7aVFmdZzwFKJn57mf3pUi5oGl5NBXQMVSWR8BVDeRtXQ2bQiz9x9hR0FUH62WMUj1V_7kcxp0O_XBEg8E3qvUT0AMObHdJc5tlzcxUOiILewAk3zwv13P_WIcQN5jaNNzsnDeo0y7UZkkvMBv6vBPfQdO61mBad4GsDOVSnj9z34ylvdDjwkMVNDUp0xYxuWDmmSGqhUEPdUOMAl1vbsjW7dwPyDvLtoEniWxhXvPSRfxcU0x3Eitg21J3SVz8DgKyzA3ASI=w956-h2048-no?authuser=0

photo
1

HI Michael,

unfortunately, the images didn't make it again. Never mind... the error regards the pressure sensor optimization. So as a workaround, switch the pressure sensor off in Locus settings > GPS&Sensors > Altitude manager.


Hope it'll help

Michal

photo
1

Hi Michal


This time I have attached the files.

The strange thing is that my pressure sensor was off.


Any advice?

Do you want the full NMEA log?


Regards

Michael

photo
1

Hi Michael, we are dealing with this problem. For the time being, set your GPS - Altitude manager - settings tab like this:

- SRTM data - select "Optimize GPS values" or "Replace values"

- Altitude filter - select medium or heavier filter

- make sure Locus Map has all location access permission set to "always" and is excluded from all means of battery optimization (see https://docs.locusmap.eu/doku.php?id=manual:faq:gps_lost_fix_android6)

Michal

photo
1

Hi Michal

Thanks a lot for the reply.

I have changed my settings as you suggested. Should that fix the problem?

My permissions and battery management was already correct.


Please let me know when this issue has been resolved.

Regards

Michael

photo
1

I've been informed by the devs that it had been resolved internally. We're just waiting for the bugfix release. It should be out in a few days hopefully.

photo