Falsche Höhenmeter Berechnung im Routenplaner? Locus Map Classic?

Stephan shared this problem 39 days ago
Not a Problem

Wenn ich mit Locus Maps eine Route plane, werden mir generell mehr Höhenmeter angezeigt, als in anderen Apps (z.B. Ride with GPS).


Ich habe auf Mallorca eine Tour zum Cap Formentor geplant. Da werden über 1800hm angezeigt. Die exportierte GPX nach Ride with GPS zeigt aber nur ca. 930hm an.

Das kann eher stimmen.


Die Wahoo Aufzeichnung sind auch immer weniger Höhenmeter, als vorher mit Locus geplant. Ca. 30% weniger.


Auch importierte Routen von offiziellen Rundfahrten, werden mit mehr Höhenmeter angezeigt, als die Touren offiziell beschrieben sind.


GPX anbei.


Ich denke Locus Map berechnet zu viele Höhenmeter. Kann das sein?


Viele Grüße Stephan

Replies (6)

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Hi Stephan,

each service or app uses different 3D landscape model and different algorithm for calculating elevation gain. Seeing the detailed elevation graph of the route you've sent it is quite clear that the terrain in many parts of the route is rugged and variable. Locus Map's accurate model catches all these terrain details which in result gets quite a high number of the total elevation gain:

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Other apps and services usually tend to generalizing such terrain details and their result may seem more "real" because people are prone to overlooking slight ups and downs on the route and reflect only heavy uphills or downlhills.

Nevertheless, as we've often been experiencing similar reports, we added an option in Locus Map 4 to set user's own "elevation threshold" tweaking the main algorithm so that the result seems more real (the threshold omits all hills up to 20 m from the total calculation)

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Dear Michal, many thanks for the detailed explanation.


But is it real? I mean, no other app shows so many height meters.


I was recording the track with wahoo roam v2 and it recorded about 940 hm.


Could that massiv peaks on the graph real? I mean, so extraordinary heights jumps were not included an the road.


Is there any way to set this option in Locus map classic?


A few meters more sounds acceptable, but double is a problem, I mean.


Thank you for quick response

Stephan

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You can filter it or use more accurate altitude data (LIDAR). If you have a barometer you can also use it.

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Dear freischneider,


The Wahoo Roam V2 has a barometer system. Is this more accurate?


But should I really made 1800 hm today? No one believes me that.


Why the Locus Map algorithm is much more accurate than all other?


I'm a big fan of Locus Map, but how can I double check the height meters on a other independently way or software??


Than I trust you and believe the 1800 hm. :)

Stephan

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I'm afraid you are mixing up two things - the planned route and the recorded track. The barometer is relevant for the latter only.

As for the planning and calculation of the elevation gain from a 3D landscape model - it is always different from the recorded track because no 3D models are as accurate as the real situation and the more complicated the terrain is the more deviations 3D models render. LIDAR elevation data can help but they are not available for every area.

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The barometer is very accurate when recording. However, changes in air pressure due to the weather can lead to deviations during the course of the day.
Locus Map regularly performs a calibration based on the altitude data.
As far as I know, Wahoo does not do this.

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The altimeter figures in GPS apps are pretty much useless.

I ride in flat terrain so collect altimeters which is therefore nonsense.

How hard the wind blows is immensely more important here ;-)

It could be useful in hilly terrain provided more useful figures.

The route PLANNING example.

The short peaks arise from the limited altitude resolution. Michal has already explained that.

If you look at the altitude graph you already can filter them out visually quite easily.

You can also easily determine the real useful heights and lows visually.

I have briefly (quickly) tested this in this way.

Determine (visually) useful height reference locations and place waypoints here.

Using the waypoints, produce a gpx route and import it into Locus.

Upon import, Locus sees this as a track and can then add the elevation.

With this more limited data, Locus will then calculate the altimeters.

Only read the altimeters, the route line distances are only useful for birds.

Do these altimeters (687m elevation gain by Locus Classic SRTM 3" files) correspond more to what you can really expect ? The many non-flatland users should test whether it is useful(er) or not.

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I analyzed the problem:

1) Stephan original track has quite wrong elevations values which sum up to a completey wrong altitude gain of 1996 m. Locus app and Locus Webplaner automatically applies a "elevation threshold" of 5m during import which calculates to an still wrong gain of 1697 m.

He wrotes that this is not a recorded track - but a planed track with Locus Maps. So the problem is within Locus'planer, and in detail in the elevation files he uses.

2) I guess he didn't used Locus Web planer, cause it calculates a total elevation gain of 886 m which is quite ok. If he had used Sonny 1" elevation files within the app, Locus Classic app calculates 972 m which seem also quite near to reality. So I think probably he used Locus Classic or Locus 4 with the usual unaccurate SRTM 3"-files which are offered by Locus for download.

3) In general Locus Web planer is lacking a function to correct the elevation values of imported GPX-tracks. If I import Stephans' track into Locus Web planer it displays the wrong elevation gain of this track (1697 m) without any function to replace its wrong values by the accurate values (Sonny 1") which Locus Web Planer usually uses.

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hmmm...Sonny the question was:

Falsche Höhenmeter Berechnung im Routenplaner? Locus Map Classic?

I don't use your data as it makes little sense to me but do follow the issue a bit.

Well to say I did try the elevation notation once ;-) See attachment.

https://help.locusmap.eu/topic/29901-allow-custom-srtm-sub-directory

Locus google play Classic (A13) in android/data blocks necessary access ?

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Hi, to be honest I'm not quite sure what you want to tell us and what the .gpx-Track is about ? ;-)

Is it something regarding the dicussed issue here, or something to do with Android's blocks and/or the file location where Locus does save its elevation files?

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Dear Sonny, that is very interesting! You are right. Locus Map Classic 3 with Locus Elevation Data for the region.


I was looking on your website. I'm impressed. How can I test your 1" Data? Is it possible to download directly from Locus for the desired location?


I just want do download just relevant regions. Is there a way to download just this Tiles?


Best regards

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Not directly from Locus yet - althouth the suggestion has been made: https://help.locusmap.eu/topic/offer-high-resolution-lidar-elevation-data


You've to download the Sonny 1" files of a whole country - or parts of it - yourself, de-zip them and copy them to Locus' SRTM-folder

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Sonny.
What I presented with this simple gpx record is that this one gives you a fair altimeter figure. Both by using the original track and if by replacing the elevation with Locus has available by default. The more accurate files (not tested) will also be solid.
Other records on the other hand, you usually don't get such a decent elevation figure in Locus Classic.
Regarding your files, a Google Play Classic user from A13 onwards can hardly still import the files anymore.

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Why shouldn't that work? With xplore or a PC you can access all folders.

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Then I ask you these questions.

A mobile phone with a PC attached to it ?

Does it work with A13 or even A14?

Access to config.cfg or TTS is idem.

Do you see this as a nice method?Or the death knell for Classic?

I know with A13 that you can also write using the somewhat "hidden" default Android file explorer if you than use dual window. Neat user-friendly all this is not anymore anyway, you know.

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Is there a way to find out, which file is for which tile of the country after download? So that I can delete the rest?


Sonny I made an upvote on your suggestion. Hopefully menion will implement it some time soon.


When I'm back at home, I will test your files. ;)

Will Locus recognize the the elevation data for the region is there or will it download and replace it with the original locus data?

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You've to check what coordinates your area of interest is within. For example your GPX-track in Mallorca is completely within coodinates N 39... E 3 , so've just to download tile N39E003.

You've just to overwrite the file N39E003.hgt being present within Locus' SRTM folder with the new Sonny N39E003.hgt Locus will not overwrite it again with its own unaccarate SRTM 3"-hgt file

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Locus will not automatically overwrite the file. But if it goes to Download elevation data in the store, the file will be overwritten.

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The altitude data will only be downloaded if you say so in the store.
Then your LIDAR will be overwritten. It is therefore best not to download anything from the store. I get all my altitude data from Sonny. Then I'm sure it's always the best.

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That worked now!! Now I get about 970 elevation meter for the tour, that seams to me fits more. :)


But the only way to copy the files is with the PC. No direct access to the folder from mobile phone device. :(

Not very comfortable. Locus Maps should use your 1" in general for download within the app.


But now I get many thin elevation lines. That looks a bit chaotic. See Screenshot. Any idea to solve this problem?


Any option to change that in openandromaps maps or theme?


:)

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All elevation lines are doubled now. :(

Don't understand that.

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