SYSSIFOSS

SYSSIFOSS is a joint project between the Institute of Geography and Geoecology (IFGG) of the Karlsruhe Institute of Technology (KIT) and the 3DGeo Research Group of Heidelberg University. In this project we suggest a new approach to create synthetic LiDAR data by combining the outputs of an established forest growth simulator with a database of species-specific model trees extracted from real LiDAR point clouds.

Find out more on our project website and watch our project video.

The repository contains the scripts used for processing our laser scanning forest data.

Repository structure:

01_tls_georeferencing

• OPALS tools for registering TLS data to ULS data:

  • stem detection: opals_stem_detection_tls.py, opals_stem_detection_uls.py

  • applying multiple transformation: opals_apply_transformation.py

  • running the ICP: opals_run_icp.py and opals_run_icp_all.py

• Execute these scripts in the OPALS Shell or from the PyCharm-distribution that comes with Opals
• RANSAC script for 2D stem matching: ransac_2d_trafo.py

02_tree_extraction:

• Scripts for automatically extracting point clouds from one point cloud using template point clouds: get2clouds_multiple_targets.py, get2clouds_ULS_ALS.py Can be used for

  • retrieving all points of a spatial subset from a large point cloud using a downsampled source (template) point cloud from the same dataset, e.g.,

    • template: Tree point cloud segmented from downsampled TLS point cloud (only x, y, z)
    • source: Full TLS point cloud (x, y, z, + other attributes like reflectance, return number, etc.)
    • output: Tull-resolution TLS tree point cloud (x, y, z + other attributes)

  • retrieving all points of a spatial subset from one dataset using a source point cloud from another dataset, e.g.,

    • template: Tree point cloud segmented from TLS point cloud
    • source: ULS point cloud of a full forest plot
    • output: ULS single tree point cloud

03_metric_computation:

• Library for the computation of tree metrics: TreeMetrics.py

• Scripts for

  • computing tree metrics, using TreeMetrics.py: compute_tree_metrics.py

  • computating of DBH: DBH_RANSAC.py, DBH_ellipse.py

  • deriving tree positions: tree_positiony.py

• External programs used:

  • Concave hull C++ program by Alasdair Craig: https://www.codeproject.com/Articles/1201438/The-Concave-Hull-of-a-Set-of-Points using the algorithm by Moreira & Santos (2007): concave.exe

  • Ellipse fitting program by Nicky van Foreest:https://github.com/ndvanforeest/fit_ellipse: fit_ellipse.py

04_opals_formatdef:

• OPALS format definitions specific to the SYSSIFOSS data.

05_database

• Scripts to write GeoJSON files and CSV files for the database from the contents of a tree data folder:
  • GeoJSONs: create_geojsons_pytreedb.py and create_geojsons_pytreedb_2.py
  • CSV: geojsons_to_csv.py

Requirements

Requirements for all non-opals scripts are found in requirements.txt

License

See LICENSE