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55 lidar

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LiDAR data analysis and visualization with whitebox and leafmap

Create a new conda env to install required packages:

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conda create -n geo python
conda activate geo
conda install -c conda-forge mamba
mamba install -c conda-forge pygis
pip install laspy[lazrs]

Uncomment the following line to install packages in Google Colab.

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# !pip install leafmap

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# !pip install laspy[lazrs]

Import libraries

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import os
import leafmap
import whitebox

Set up whitebox

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wbt = whitebox.WhiteboxTools()
wbt.set_working_dir(os.getcwd())
wbt.set_verbose_mode(False)

Download sample data

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url = "https://opengeos.org/data/lidar/madison.zip"
filename = "madison.las"

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leafmap.download_file(url, "madison.zip", unzip=True)

Read LAS/LAZ data

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laz = leafmap.read_lidar(filename)

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laz

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str(laz.header.version)

Upgrade file version

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las = leafmap.convert_lidar(laz, file_version="1.4")

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str(las.header.version)

Write LAS data

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leafmap.write_lidar(las, "madison.las")

Histogram analysis

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wbt.lidar_histogram("madison.las", "histogram.html")

Visualize LiDAR data

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leafmap.view_lidar("madison.las")

Remove outliers

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wbt.lidar_elevation_slice("madison.las", "madison_rm.las", minz=0, maxz=450)

Visualize LiDAR data after removing outliers

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leafmap.view_lidar("madison_rm.las", cmap="terrain")

Create DSM

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wbt.lidar_digital_surface_model(
    "madison_rm.las", "dsm.tif", resolution=1.0, minz=0, maxz=450
)

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leafmap.add_crs("dsm.tif", epsg=2255)

Visualize DSM

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m = leafmap.Map()
m.add_raster("dsm.tif", palette="terrain", layer_name="DSM")
m

Create DEM

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wbt.remove_off_terrain_objects("dsm.tif", "dem.tif", filter=25, slope=15.0)

Visualize DEM

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m.add_raster("dem.tif", palette="terrain", layer_name="DEM")
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Create CHM

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chm = wbt.subtract("dsm.tif", "dem.tif", "chm.tif")

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m.add_raster("chm.tif", palette="gist_earth", layer_name="CHM")
m