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Locus Map - help desk Topic Question Locus Map (Android)

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Category Locus Map (Android)

Tags elevation gain

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Subscribers 5

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Elevation gain - unreal (after saving the track)

Jaroslav Matyáš shared this question ago

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My last two tracks are displaying unreal elevation data. Just take a look at the min/max altitude at my screenshots and it must be clear to everybody. Elevations gain used to be OK in my previous tracks. Am I doing something wrong?

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The same question

Replies (3)

Michal Stupka ●

Hi,

elevation gain is calculated as total sum of all ascended meters on the track, not just subtraction of maximum and minimum altitude. When the track is hilly the elevation gain may result in such values. Sometimes, especially when your track goes horizontally on a slope side, unacceptable deviations may occur due to faulty GPS data received by your device, influenced by the character of the terrain. If it is so too often, you can try optimizing your altitude measurements in Locus settings > GPS&sensors > Altitude manager. You can optimize by SRTM data, by barometric pressure or by several levels of filters.

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Jaroslav Matyáš ●

I'm sure I understand what elevation gain means :) To gain 1700 m on 3 hours easy biking around Lednice/Valtice with my wife is just impossible. After uploading the file to Strava I get 300 m gain and that's much closer.

Ok, I will play with settings. But I doubt it will help to correct such a huge inaccuracy.

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Menion ●

Hello Jaroslav,

may you please export & share a GPX file of your record with us? I really would like to check, why is there such huge difference compare to reality, thank you!

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Jaroslav Matyáš ●

Hi Menion

Pls see the attachments:

mtb-lednice-valtice: overrated elevation gain
speed-hiking-male-karpaty-zaruby: overrated elevation gain
speed-hiking-schneeberg-novembergrat-herminensteig: elevation gain looks OK

Thanks

Jaro

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Menion ●

Hello Jaro,

thanks for the files. Firstly, it looks that you GPS is really sensitive in Z (altitude) axis in case, it has low satellite signal. Result is, that in case you are somewhere in the building etc, it returns position, but with really bad altitude.

With your recorded MTB lednice, I tried for example http://utrack.crempa.net/ . Result?

Google Earth, result:

/wG45usIolj87AAAAABJRU5ErkJggg==

And so on. So main problem: recorded elevation values in few places, that resulted in huge elevation changes.

Solutions:

after track recording finish, use in track detail, bottom right menu > more > update elevation. Result? Elevation loss -387m, elevation gain +387m
optimize Altitude manager. Open menu > settings > GPS & sensors > altitude manager. In your case, I suggest enabling "Replace GPS values" in "SRTM data" section. Be sure, you have download elevation HGT files (for example over Locus Store).

I did not write exact details, so feel free to ask if some information are not clear how to do. We have manuals for most of these steps, so I may simply forward you to correct place.

Menion

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Jaroslav Matyáš ●

Thank you Menion. It looks like both suggestions work.

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Stefan Eckel ●

I was Just thinking about a ticket with same problem. I am using Locus for a while, but always with imported Tracks. Today I tried to record a track with profile biking. The terrain was easy 1250 m up and down without any loss of altitude while going uphill. Locus shows 3870 m elevation - up and down almost equal. The unreal values are shown while recording and after saving Thomas track. Settings are all default with metric Units. The values look like there is a problem in Translation from feet into meters?

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Michal Stupka ●

Hi Stefan, you can try optimizing your altitude measurements in Locus settings > GPS&sensors > Altitude manager. You can optimize by SRTM data, by barometric pressure or by several levels of filters.

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