Elevation and slopes completely off

Hi Clem,

could you please specify where exactly this problem occurs? Could you send a GPX of the route so that we can evaluate all circumstances? Do you also have any reference measurements of the elevation gain? The more info you give, the better help we can provide. Thanks!

Hi Michal, thanks a lot for you answer. For instance, here is the route planned today forecasting more than 2000m cumulated elevation https://link.locusmap.app/t/iviv53 and here is my today's track which is actually 370m https://link.locusmap.app/t/p7bkyb

Hope that helps, let me know if you need any other information and thanks a lot for you help !

There is a tiny tunnel km 2 and a bridge here but it happens also without any tunnels or bridges. Thanks !

Hi Clem,

thanks, could you please send GPX files of both the route and the track? Did you plan the route on the web or in the app?

Hi Michal,

That's what I did in my first reply with the links. Here are the files if it's easier. I used the app to plan. Let me know if there something i'm missing

Hi Clem,

Thanks for testing that, and sorry again this cropped up mid-trip.

The elevation profile filled onto the planned route is full of tiny artificial up-and-down steps, and since total ascent adds up every little rise, that noise balloons into a hugely inflated number (and drives those unrealistic slope readings too).

Since recomputing the elevation didn't help, the most likely cause is simply that the elevation source data for this area isn't very accurate — especially where your route runs along the side of a ridge, where the elevation grid can pick up ground higher or lower than the road itself. So it's not your route or the terrain; it's the underlying data.

The good workaround is the one you can apply per route: set a custom altitude (gain) threshold for that route from its elevation profile settings, instead of relying on the global default. A threshold of around 20 m brings the total down to a realistic ~515 m — much closer to what you actually ride. You can nudge the value up or down a little to taste. For recorded tracks, the elevation is reliable as-is, so trust those for your real totals.

Enjoy the rest of the trip!

Hi Michal,

Thanks a lot for your help. Can you détail how you are doing that ? Is it à global setup or i will have to tweak every route ?

Its not just à local issue as its the same for Bosnia, Serbia, Kosovo... do you think using OSM instead of LoMaps can be better or it's going to be the same ?

Thanks !

OSM maps, LoMap, OAM maps, etc., are all based on OSM raw data and are therefore the same.

But when it comes to elevation data, there are good and very good options. Sonny’s LiDAR data is currently the best. However, it requires a bit more storage space. The accuracy of the recording can also vary depending on the GPS sensor and how many points it captures. The recording should follow the route as closely as possible.

Translated with DeepL.com (free version)

Hi Clem,

The altitude threshold is applied individually because the data noise is not present everywhere, but it is quite common when the route runs along the side of a hill or ridge.

It has to be enabled in the expert settings, and then it is available in the "edit" dialog for the route. More info: https://docs.locusmap.app/doku.php/manual:faq:wrong_gps_data#custom_altitude_threshold.

As for the elevation data, you can download the custom data @freischneider mentioned but not all countries are covered by the most accurate lidar data. More info: https://docs.locusmap.app/doku.php/manual:faq:how_to_add_map_shading#custom_elevation_data_sources

Great, thanks a lot to borh of you for your help !

About the slopes, any idea how to make them more accurate ? Even when applying the threshold or in countries with less noise, the slopes are completely off

Thanks !