GRASS GIS – How to Import LiDAR Data in GRASS 7

grassimportlasliblaslidar

I compiled GRASS 7 on Ubuntu 12.10, with liblas in order to run r.in.lidar and v.in.lidar. I now want to import .las data; the option in file -> import raster data -> LAS LIDAR points import is given and enabled, but when I select it nothing happens.

It seems to be a problem with libLAS. The console error message says:

Unable to fetch interface description for command 'r.in.lidar'. Details: r.in.lidar: error while loading shared libraries: liblas_c.so.2.2.0: cannot open shared object file: No such file or directory.

Addition: running lasinfo from terminal works.

Any idea where the bug could be?

Best Answer

Problem solved. Did a make clean (that is what I omitted before), then again $ "-g -Wall" ./configure --with-liblas=/usr/local/bin/liblas-config, followed by make and sudo make install. Works now!

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[GIS] QGIS error when importing .asc LIDAR data

The quickest solution would be to load the data into LibreOffice Calc, and sort the data on the second column, then the first one ascending. The result should look like:

426000.78;55000.15;562.24 
426001.78;55000.15;562.22 
426002.78;55000.15;562.20
426003.78;55000.15;562.30
426004.78;55000.15;562.21
426005.78;55000.15;562.21
426006.78;55000.15;562.27
....
426000.78;55001.15;562.96
426001.78;55001.15;562.22

Saving to csv should give you the right format for GDAL.

See http://www.gdal.org/frmt_xyz.html for more details.

UPDATE

Looking at the whole dataset, your grid has no constant cell size, maybe due to reprojection from another CRS.

So your only chance to use the data is to round the data to full meter cell size, or import it as delimited text point layer, then run Raster -> Interpolation -> Interpolation on it.

[GIS] Importing LiDAR (.las) data in PostgreSQL with PDAL

As HowardButler stated you need to use the JSON option for any PDAL version over 1.5. I am using PDAL version 1.7.2 and PostGreSQL version 9.6.

1) Create a text file using NotePad as described below. This particular JSON script reads from a standard .LAS file and writes to a PostGreSQL database table. The PostGreSQL database has the pointcloud and postgis extensions enabled. The lidar records go in as patches (groups) of 600 per database record. I don't know why they call them "patches" but that's what they decided to name them. Note the double \ in the filename path. JSON doesn't like single backslashes so you need to escape them. Save the file as theNameOfYourJsonFile.TXT. Obviously you will change the SRID to whatever is appropriate for what you are working on.

{
  "pipeline":[
    {
      "type":"readers.las",
      "filename":"C:\\foldername\\foldername\\foldername\\nameOfLasFile.las",
      "spatialreference":"EPSG:26916"
    },
    {
      "type":"filters.chipper",
      "capacity":600
    },
    {
      "type":"writers.pgpointcloud",
      "connection":"host='localhost' dbname='nameOfYourDb' user='yourUserName' password='yourPassword'",
      "table":"pcpatches",
      "compression":"dimensional",
      "srid":"26917"
    }
  ]
}

2) I am using the Windows version of PDAL that came with OSGeo4W so in my case I then open the command window to run the next step. If you are using a different operating system you may need to do this next step differently. At the c: prompt in the command window type in the following:

         pdal pipeline -i C:\foldername\theNameOfYourJsonFile.txt

The pdal pipeline command will run using the JSON from the text file you made. JUST LET IT RUN! It might take anywhere from a few minutes to 10 or 15 minutes. Remember point clouds are HUGE! When complete you will have a PostGreSQL table with your lidar records imported. Each record will contain groups of 600 points that can be extracted using SQL. Here is one way to view the data, there are many other ways available:

SELECT PC_AsText(
PC_Explode(nameOfFieldThatContainsYourPatches))
FROM tableName;

Best Answer

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[GIS] QGIS error when importing .asc LIDAR data

[GIS] Importing LiDAR (.las) data in PostgreSQL with PDAL

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