Collect and combine open elevation data to implement 3D terrain model/hillshading/relief maps

[biodranik]

Now we use SRTM elevation data and embed it into isolines. The idea is to store the whole planet's elevation more efficiently, to allow calculation of the elevation anywhere, and to draw isolines of any density.

To improve the elevation precision we need more data to improve the SRTM quality. Some elevation data can be taken from publicly available OSM nodes, ways, and imported tracks.
Some data can be taken from other sources, like this one for Europe: https://land.copernicus.eu/pan-european/corine-land-cover/clc-2006

Please share other sources and your ideas on improving the elevation data quality here.

[Popolon]

FLOSS Flightgear flight simulator uses several sources for years for the the default scenery elevation including SRTM and Corine, they work could be a source of inspiration.

https://wiki.flightgear.org/TerraGear_CORINE#III._Corine_landclass

They made a tool called TerraGear for generating scenery from all these sources. I'm not sure it could be useful itself for Organic Maps, but they have an interesting list of open data for elevation/roads/coast/buildings. They use OpenStreetMap for buildings.
https://wiki.flightgear.org/Using_TerraGear#Obtaining_and_processing_data

Some hand made 3D textured objects help for some specific landmarks too. As they are available under open licence too with exact coordinate. But I believe their could be reused, but the details are generally made to be seen by plane, not sure it will be useful for OM.

[not-available-username]

This is the source mentioned in the OpenTopoMap: http://viewfinderpanoramas.org/

[not-available-username]

It is possible to have more dense isolines? It helps while the hillshading is not available, thanks.

[AccessViolation95]

This is a recently released lidar heightmap of all of the Netherlands: https://www.ahn.nl/ahn-viewer

It's a fairly high resolution with on average 8 measurements per 1 m². Definitely enough for very precise road elevation usable in routing, but it isn't hole-filled, which might be preferable for if road geometry changes over time and no longer lines up with the height map.

I think possibly more valuable data for routing could be GPS traces. They can be contributed to OSM by many apps including some navigation apps like OsmAnd. If you could somehow download these, fuse them and give that data to the routing engine that might be nice. Could even have this as an option: "Anonymously submit sections of your driven route to OpenStreetMap to improve routing and help map contributors?"

Since OM has privacy as one of the main features, maybe the app could also/only record and use these locally without contributing them, so the app can get a better idea of actual road height as it is used.

[biodranik]

It is possible to have more dense isolines? It helps while the hillshading is not available, thanks.

It is possible, but the map size will increase significantly, and the rendering speed will decrease noticeably. That's why we want to create a full 3D terrain model. Then isolines of any density can be generated "on the fly".

[biodranik]

Useful links:

• https://www.opendem.info/link_dem.html
• https://en.wikipedia.org/wiki/National_lidar_dataset
• https://en.wikipedia.org/wiki/National_Lidar_Dataset_(United_States)
• http://esri.github.io/lerc/
• https://www.gpsvisualizer.com/elevation

[pastk]

It is possible, but the map size will increase significantly, and the rendering speed will decrease noticeably. That's why we want to create a full 3D terrain model. Then isolines of any density can be generated "on the fly".

Are there ideas how to produce isolines from a 3D model "on the fly" in a fast and efficient manner?

Existing isolines are pre-generated, so its just ordinary lines that need to be rendered.
If they need to be generated first then its an extra step before (and likely computationally expensive one)..

[biodranik]

[SonnyLidarDTM]

There a precise, free elevation source for European countries which is already used by many map providers or creators of accurate sceneries for flight simulations: Sonny's Lidar DTMs
Comments possible in thread: #7480

[pastk]

Here is another good overview of available elevation datasets: https://github.com/DahnJ/Awesome-DEM