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28 votes
Accepted

numpy array to GTiff using rasterio without source raster

This ended up being more straightforward than I thought, with all of the capabilities lying in the rasterio.open function. Here is an example using a proj4 string instead of wkt. import rasterio ...
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20 votes

What are LiDAR returns?

ESRI has a pretty good help section on LiDAR (below). For more formal details on LiDAR, I would recommend the following books: Topographic Laser Ranging and Scanning: Principles and Processing ...
  • 50.7k
20 votes

QGIS 2.14.1 LAStools install error: "wrong value for parameter 'Msys folder'..."

According to Diego Alonso's comments from the mappingGIS blog1, this error is related to QGIS version 2.14. With the upgrade, the standalone installer eliminated the msys folder from GRASS 7 ...
19 votes
Accepted

Seeking point cloud (LiDAR) data?

I decided to merge other answers with mine and organize them into a tabular format. I think it is easier to read and manage for future visitors: The table can be accessed from the following link in ...
19 votes
Accepted

Convert hdf5 LiDAR data (from GEDI) to LAS or LAZ

It's not possible to convert GEDI .h5 file to LAS file as including all data. Because .h5 file includes a lot of information about a point (actually it is a window in GEDI .h5 format, not a point). ...
17 votes

Viewing LIDAR data (.las) in QGIS?

QGIS 3.18+ supports point cloud visualisation natively.
  • 1,168
15 votes
Accepted

Benefits of *.las vs *.xyz or *.ascii when working with LiDAR in ArcGIS for Desktop?

ArcGis has a new LiDAR dataset at 10.1 which will allow you to view your LiDAR data directly and also see more information than what's in a raster... for example you can add to ArcMap and then filter ...
14 votes
Accepted

Converting LAS 1.4 to 1.2

For converting to las 1.2 from las 1.4, PDAL's translate command is an option: pdal translate --writers.las.minor_version=2 input-las14.las output-las12.las LAStools can also do the job: las2las -i ...
13 votes
Accepted

Reprojecting LiDAR data with libLAS, error: "latitude or longitude exceeded limits"?

Set the scaling and offset when reprojecting to WGS84, e.g.: las2las --a_srs EPSG:26911 --t_srs EPSG:4326 -i file1.las -o output.las --scaling 1e-7 1e-7 0.01 --offset <something close to your data'...
13 votes

Thinning large LiDAR point cloud?

It sounds like you want either a voxel-based thinning or maybe a Poisson-based one. PDAL can do either. See PDAL's tutorial on the topic at https://pdal.io/tutorial/sampling/index.html . As far as ...
12 votes
Accepted

Methodology for creating accurate drainage networks (and catchments) from high resolution LiDAR DEM?

Have you consider to use GRASS GIS analysis? I have expirience that GRASS algorithms have very good accurance on hydrology analysis. For example, I want to generate something like drainage network on ...
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12 votes
Accepted

Cleaning blocks pattern from urban LIDAR (blocks uplifted from streets)

If you are open to using alternative software to solve your problem, then I can suggest the Remove Off-Terrain Objects tool of the cross-platform open-source GIS Whitebox Geospatial Analysis Tools (of ...
  • 10.9k
12 votes

Difference between LAStools, libLAS and PDAL?

The answer by Howard Butler pretty much sums it up. Some more background. When I created the first LAStools and the LASlib library that the tools are build upon I was a postdoc at UC Berkeley and ...
  • 1,144
12 votes
Accepted

LAStools plugin in QGIS: ''The system cannot find the path specified."

Be aware one needs to have the LAStools plugin installed, but also the software per se. The LAStools plugin description says: ... . You also need to download the LAStools software from http://...
11 votes

What LiDAR processing tools are available in Python?

I have recently released an open-source (MIT) stand-alone (i.e. no dependencies) library called WhiteboxTools for performing many types of geospatial analysis, including LiDAR data processing. The ...
  • 10.9k
11 votes
Accepted

Extracting tree crown areas from remote sensing data (visual images and LiDAR)

There is a considerable body of literature on individual crown detection in spectral and lidar data. Methods wise, perhaps start with: Falkowski, M.J., A.M.S. Smith, P.E. Gessler, A.T. Hudak, L.A. ...
11 votes
Accepted

Assigning RGB values from Geotiff image to LiDAR data, using R

Thank you for clarifying your question as it was previously quite unclear. You can read a multiband raster using the stack or brick function in the raster package and assign the associated RGB values ...
11 votes

Benefits of *.las vs *.xyz or *.ascii when working with LiDAR in ArcGIS for Desktop?

If you have the opportunity to get LAS or LAZ instead of TXT ... absolutely go for it. It will be trivial for you to go from LAS or LAZ to TXT (for example with the free and open source las2txt tool ...
  • 1,144
10 votes

Working with LiDAR data using other than Esri software?

Since this is being linked to by https://gis.stackexchange.com/questions/132591 (since deleted) I'll add my own two cents with some more free and open-source tools. First, for command-line/batch ...
10 votes

What are LiDAR returns?

The picture below from Fernandez-Diaz (2011) might help complementing Aaron's answer. Lidar returns are discrete observations* recorded when a laser pulse is intercepted and reflected by targets. ...
10 votes
Accepted

Difference between LAStools, libLAS and PDAL?

libLAS was developed to provide read/write support for LAS and it was modeled on LAStools which at the time was not released under an open source license. In the subsequent years, many parts of ...
9 votes

LiDAR data density, returns per square meter

I develop a free and open-source GIS called Whitebox Geospatial Analysis Tools (can be downloaded here) that has extensive analysis functionality for processing LiDAR data. Whitebox contains a tool ...
  • 10.9k
9 votes

Creating DEM from geoTIFF or asciiGRID LiDAR data?

You already have a DEM; there is no need for you to create one. The DEM is contained within your files, i.e. you have two copies of the DEM, one contained within an ArcGIS ASCII raster and the other ...
  • 10.9k
9 votes
Accepted

Use laspy to create las file from scratch without opening an existing las file first

Rather than setting the entire points array in one go, try setting each dimension in turn: import laspy header = laspy.header.Header() outfile = laspy.file.File("output.las", mode="w", header=header)...
9 votes

Converting between coordinate systems for LAS file using LASPY

You should check what the scale and offset are for your file. This can be done as follows: van_taken.header.scale van_taken.header.offset This almost looks like an overflow error to me. The lower ...
9 votes
Accepted

Finding pixels in DEM with 5% slope or less?

You mention 3D Analyst so I am assuming you have ArcGIS. Use the tool ArcToolbox-3D Analyst Tools-Raster Surface-Slope to create a slope surface from your LiDAR data. Use the tool ArcToolbox-3D ...
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9 votes
Accepted

Editing LiDAR point cloud to remove noise/outliers present below and above ground?

You seem to have outliers: i) below the ground surface; ii) above the ground surface and vertically among other above ground real features; iii) above ground points with height greater than all ...
9 votes

Installing LAStools in QGIS 3.0?

Install QGIS 3.2 and goto the plugin manager. A brand-spanking new set of LAStools toolboxes can be found by searching for LAStools in the Plugin repository or download the latest version here: http:/...
  • 1,144
8 votes
Accepted

What's the deal with "degradation" and lastools?

Many of the LAStool readme files have a paragraph like this: Please license from martin@rapidlasso.com to use lasclassify commercially. Please note that the unlicensed version will set ...
8 votes

Georeferencing LAS files in geographic coordinates (lat/lon) or in cartesian (projected) ones?

It depends on what version of the LAS specification you are using. If it is 1.3 or less, then the specs define georeferencing information using pre-defined (see specs) variable length records (VLRs) ...
  • 10.9k

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