jbbarre / lidarhd_ign_downloader

Python script to download and resample LiDAR HD from IGN.

IGN LiDAR HD downloader

Python CLI script to download and resample LiDAR HD classified point clouds from IGN-France.

To have some news about data processing, please visit IGN-France website.

Required packages

• python (conda) environment
  • python>=3.10
  • pdal==2.5.6
  • draco=1.5.6 (we should specify draco version because there is an issue on the latest conda python-pdal version)
  • python-pdal
  • untwine
  • geopandas
  • python-wget
  • pathlib2
  • tqdm

Clone github repository

In order to install properly, you have to clone lidar_ign_downloader repository.

git clone https://github.com/cusicand/lidarhd_ign_downloader.git
cd ./lidarhd_ign_downloader

Installation

Most of the libraries required for this script are standard and are often pre-installed in conda python environments. Please follow the instructions below depending on your requirements.

If you already have a conda python environment pre-installed, please follow the instruction in section Install on pre-existing conda python environment section. Otherwise, you will need to install a conda python environment to use this script. Instructions are given in the section Install packages on a new conda python environment.

Install packages on an existing python environment

Run the next command lines in your command-line prompt:

conda activate <your-env-name>

conda install -c conda-forge pdal==2.5.6 draco=1.5.6 python-pdal gdal untwine geopandas python-wget pathlib2 tqdm

We encourage the use of mamba since this library as is faster than conda. If you want to use mamba, run the following lines:

conda activate <your-env-name>

mamba install -c conda-forge pdal==2.5.6 draco=1.5.6 python-pdal gdal untwine geopandas python-wget pathlib2 tqdm

Install packages on a new python environment

If you want to create a specific python environment, please follow the instructions below.

Python environment with Miniconda

Go to the Miniconda website and download the lastest version of Miniconda. Detailed instructions on how to install conda python environments for your operating system are available on the Anaconda website.

Once conda installed, you can

Create the new environment using mamba

First, install mamba

conda install -n base -c conda-forge mamba 

then, install all packages using the pdal_env.yml file provided.

mamba env create -f pdal_env.yml

To active the environment, type conda activate pdal_env

Create the new environment using conda

conda env create -f pdal_env.yml

To active the environment, type conda activate pdal_env

Make python script executables

If you want to run the script anywhere in your computer from CLI, you need to add the following lines to your .bashrc file to have full access to scripts. Open your .bashrc file using vi ~/.bashrc or nano ~/.bashrc and copy the following lines at the end.

export LIDAR_PATH=$HOME/lidarhd_ign_downloader
export PATH=$LIDAR_PATH:$PATH            
export PYTHONPATH=$LIDAR_PATH:$PYTHONPATH

Once changes saved, run chmod +x lidar_downloader.py into github repository to ensure the execution of the script.

Use source ~/.bashrc to reload changes.

How to use

Iside the command line prompt, type python lidar_downloader.py -h to access to the help of the tool.

This small tool needs and Area of Interest (AOI) in shapefile format as mandatory argument.

Then, we can switch between several parameters like:

some_amazing_name.shp. Then, we can switch between several parameters like:

• -out_data or --out_data_path to select specific path.
• -tr or --dem_resolution to select the desired resolution of the output DEM.
• -dtype or --file_data_type to switch between GTiff and VRT files.

Below is an example using the supplied shapefile:

lidarhd_downloader.py aoi_double.shp -out_data /home/user/some/path/directory/ -tr 1 -dtype GTiff or

lidarhd_downloader.py aoi_double.shp --out_data_path /home/user/some/path/directory/ --dem_resolution 1 --file_data_type GTiff

NOTE: The script will iterate through all the features (polygons) within the shapefile crating a folder for each specific AOI. For that, you need to specify a column with the aoi_name.

Contact and citation

For any question/bug/issue, please report it on issues section or contact [e-mail]

Please cite this tool using the following DOI