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free countrywide lidar data in PGC? (open data movement)

+2 votes
108 views
In the meantime, many countries have made their lidar elevation data available free of charge. Are there any efforts on the part of Project-GC to integrate these data, which are better in resolution and accuracy (in comparison to SRTM90) for the height information, into the height database?
asked May 4 in Feature requests by smellfooth (3,600 points)
Do you have some example of such data and such country? I see this for the first time.
For Sweden you can check this information (https://rapidlasso.com/2018/12/18/in-sweden-all-they-wanted-for-christmas-was-national-lidar-as-open-data/). I don't understand Swedish, so it is quite difficult to navigate through the webpage of lantmateriet. If you need more samples you can check https://www.geodaten.sachsen.de/batch-download-4582.html (only in German)
If you need help for processing don't hesitate to can ask me. Which fileformat would you prefer?
I don't know if PGC is using it or not (that would be sweet though) but here's a link to the US 3DEP viewer. Some locations have 1 meter DEMs (which are awesome) but most of the country is only available in 1/9 or 1/3 Arc-second.
*I just realized I didn't actually give a link https://apps.nationalmap.gov/3depdem/

1 Answer

0 votes
Sounds interesting. Our internal elevation service is built upon multiple services where it tries to use (what we believe to be) the best one first, if that doesn't have data, fallback to the next one and so on. Also based on bounding boxes of course. This makes it fairly easy to add new data sources.

I started to look at Sweden's data. It's linked from here: https://www.lantmateriet.se/sv/Kartor-och-geografisk-information/oppna-data/ . Fetched from the "Hämta via FTP", an account is needed though. But there is also a Language-select top left.

Sweden has two data-sets, they are described at https://www.lantmateriet.se/sv/Kartor-och-geografisk-information/oppna-data/#faq=b47b

The article at rapidlasso.com says there are 1-2 measurements per m2, as I understand it. But the FAQ I linked says that the data only has one measure point per 50 meters, which is only slightly better than SRTM90. However, the data itself might very well be better.

The data at Lantmäteriet is in geotiff. I don't have a generic geotiff reader in hand, so I would have to write that (and learn the format). It doesn't seem like the most advanced task though.

As you can imagine I understood less of the Sachsen data.

The biggest problem in my opinion though is that this would end up with many many different sources that should be updated regularly. Probably with different code for each country as well. It's not very smooth.
answered May 5 by magma1447 (Admin) (219,030 points)
Maybe Sweden and Saxony wasn't the best examples. In case of Sweden the resolution of the dataset isn't the best and of course the German page is only in German. Maybe a alternative will be Norway - https://kartkatalog.geonorge.no/?text=dtm&organization=Kartverket&DistributionProtocols=Nedlastingsside&type=dataset&DistributionProtocols=Geonorge
The "Laserdata Skog" that we use for looking at forrest data has the denser data  points with 1-2 points per square meter.
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