LiDAR Data

Josh Hopkins's Avatar

Josh Hopkins

05 Feb, 2018 08:53 PM

Requesting two options for working with LiDAR data. Either 1.) The ability to enable available LIDAR data sets in the Base Layers dropdown, which I'm sure is probably very difficult given the variety of LIDAR data sources. The other option would be to either link to (HTTP) or upload custom .LAS files into your account.

  1. Support Staff 1 Posted by matt on 06 Feb, 2018 05:39 AM

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    More details provided in a separate email, but for the record, .LAS file support is not something I'll probably ever support, since it's a point cloud and not even an elevation raster.

  2. 2 Posted by Tom Cal on 26 Jan, 2019 03:39 PM

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  3. 3 Posted by Tom Cal on 26 Jan, 2019 04:01 PM

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    Can an elevation raster be created from a LIDAR point cloud? https://www.google.com/search?q=lidar+point+cloud+elevation+raster

  4. Support Staff 4 Posted by matt on 26 Jan, 2019 10:35 PM

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    Yes, there are tools out there to convert point cloud data to raster data. No, CalTopo is not going automatically to do this in house on user-uploaded datasets.

  5. 5 Posted by krajnika on 05 Feb, 2019 06:11 PM

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    Matt,

    Thanks for an outstanding product!

    I understand that it's not feasible to have caltopo automatically convert point cloud data to elevation rasters, but is it possible to upload custom raster data into caltopo? (For instance, if I were to convert it myself, would caltopo be able to use that data?)

    I'm specifically interested in being able to create maps with higher-resolution hill shading based on LIDAR. I use caltopo for rock climbing, and having more granularity in the hill-shading can be tremendously useful. (With LIDAR, the exact shape of a cliff, large individual boulders, etc. become visible.)

    Right now, I'm just using the geospatial image feature to do this. I copy a high-rez hill-shaded image from open-source LIDAR data, and load it into caltopo as a geospatial image. It's finicky to get the terrain lined up, but I can then use this layer at partial transparency to lend additional detail to the map.

    Basically, I'm looking for a better way to do this (Without having to manually align the image to the map.) Is this currently possible, or is there any future development that might support this?

    Thanks,

    Andrew Krajnik

  6. Support Staff 6 Posted by matt on 06 Feb, 2019 06:29 AM

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    You can't import your own LIDAR data, at the moment what you're doing is pretty much the best way. The only improvement would be to tile the hillshade using something like gdal2tiles, host it online on something like Amazon S3, and then add it as a custom source. That way the image size isn't limited and you don't have to manually align it by hand.

    I don't see custom elevation sources being supported. The existing data is in a somewhat custom format that would be hard to replicate (standard PNG tiles, but using RGBA bands to store elevation plus precomputed slope and aspecft), and there's some interplay between front end and back end that would add to the complication of using other formats.

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