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Tutorial: How to convert raster DEM/DTM/DSM to LAS/LAZ classified cloud point Lidar

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  • jpotas
    commented on 's reply
    CSV is convertable to LAS format. I have done it using QGIS and LAS Tools. A pain but it can be done. Had to figure it out in order to do Mountain Ash GC in Wales.

  • Myron Bedford
    replied
    Also is there a way of converting .tif files? I twould masiively increase the amount of B.C courses somebody could put in.

    Leave a comment:


  • RVPar
    replied
    I'd like to try my hand at designing my home golf course but LiDAR files are not available in rural Alberta. The file format available at the Town website are: shp, kml and CSV format, do you know if these can be converted to LiDAR files. I believe this data is a free download but I think you need an open data license to login. This is where I'm out of my element. Is there anyone who can download and convert these files for the right format to use in Chad Tools and OSM? If so I'd be interested if this is a possibility.

    Leave a comment:


  • David Shen
    commented on 's reply
    My pleasure. 😃

  • Brettster
    commented on 's reply
    That makes you an 'expert' David Shen - I know it can take hours and hours, and hours and hours going through all of that material and presenting it in a way that makes it so much easier. So, Thank You again.... really appreciate having that.

  • David Shen
    commented on 's reply
    Sorry, I don't know that. 🤦‍♂️

  • David Shen
    commented on 's reply
    No, I am totally not a expert. I red a lot of articles and watch a lot of YouTube guides, and did a lot of test. Finally, I am luck to find this way. It's not a normal way. 😂

  • Brettster
    replied
    Awesome David Shen . Very well done tutorial . Looks like you are becoming the expert on conversion of these other formats into .las

    Leave a comment:


  • kgcrob
    replied
    Thank you very much for the tutorial!

    Currently, I'm looking for Lidar files for an Austrian GC, but could only find .hgt files here (includes English description). As per description, I have the impression that these are Lidar files. The files can be downloaded here and will become unzipped like N46E010.hgt

    Is there a chance to convert those .hgt files with your method into .las files?
    Thanks!

    Leave a comment:


  • Tutorial: How to convert raster DEM/DTM/DSM to LAS/LAZ classified cloud point Lidar

    In this tutorial, I will show you how to convert DEM/DTM/DSM files to LAZ/LAS files. Because Chad's Tool is only support las/laz file format (classified cloud point Lidar file). But the lidar data not cover all the place, somewhere we only have DEM files. DEM file is not perfect, it only provide the ground elevation, no trees, buildings information, but have something is better than nothing. The DEM, DTM and DSM is very similar file format, we use same way to convert them to las/laz format. In this tutorial, I just show you how to convert dem to las/laz. LAZ file is zipped las file, so laz file is better than las.

    Tools we need here are all totally free.
    The first tool is QGIS, and you must install an plugin "Lastools", we will use this LasTools later.
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    The other freeware we need is SAGA
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    After you install those freeware and plugin, now we get started.

    1. Drag and drop the DEM file into QGIS and open its properties, record the ESPG and Projections value, we will use this values later.
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    2. Convert Raster DEM to GRD format. I create a folder "D:\LIO". You can create any other folder name you like.
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    3. Now we open SAGA software. Open the upon output .grd file with SAGA, you can drag and drop the .grd file into SAGA.

    4. Look for tool "Point Cloud from Grid Point" in SAGA, and convert it to point Clouds format.
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    Conversion interface:
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    5. Look for tool "Export Point Cloud to Text File" in SAGA, to export txt file. I export all the .txt file into "D:\LIO" folder, we will use this folder later. You can create any folder name you like.
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    Exporting interface 1:
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    Exporting interface 2:
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    6. Go back to QGIS software.

    7. Look for the tool "txt2las" in "LasTools" plugin. Double click to run it.
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    8. Set all the values as below, the most important thing is to set all the point type to 2 (ground type), use "-set_classification 2". Otherwise Chad's tools won't recognize the point type, and report an "unclassified cloud point" error message. The EPSG and Projections value, we already got them instep 1, now input them. Output file size select LAZ. LAZ is a better file format than .LAS. Chad's tool can support laz files very well. You can run single file conversion, or you can also run batch conversion for multiple files in same folder. Please refer the following to screenshot, one for single file, one for multiple files.

    Convert single file.
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    Convert multiple files.
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    9. Done. Congratulations. You learned all what I know.
    Last edited by David Shen; 03-29-2021, 04:09 AM.
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