rxp-pipeline

Methods used by UCL Geography to preprocess registered .rxp data to allow further processing. The pipeline uses PDAL and requires installation of the Python bindings.

File structure

File structure should be as below where ScanPos001, ScanPos002, ... ScanPosXXX are the raw date from the scanner and matrix are derived RiSCAN Pro. Anything in extraction is temporary and could be deleted i.e. don't put anything in there that needs to be kept. clouds are the individually extracted trees, these can be either leaf-on or -off, conventaional naming is <plot>_<year>_T<num>.ply where <num> can be random or a tree tag (maybe need a different suffix to decipher this). models contain output from TreeQSM or treegraph, if there are both then put in separate directories.

20XX-XX-08.XXX.riproject
  ├── ScanPos001
  ├── ScanPos002
  ├── ScanPosXXX
  ├── matrix
  |   ├── ScanPos001.DAT
  |   ├── ScanPos002.DAT
  |   └── ScanPosXXX.DAT
  ├── extraction
  |   ├── rxp2ply
  |   |   └── <tiles created by rxp2ply.py
  |   ├── downsample
  |   |   └── <tiles created by downsample.py
  |   ├── fsct
  |   |   └── output from FSCT
  |   └── tile_index.dat
  ├── clouds
  |   └── <trees extracted with FSCT or other>
  └── models
      └── <QSMs from either TreeQSM or treegraph>

Compiling PDAL with python bindings and .rxp support

Before installing PDAL you could instead: conda activate /home/ucfaptv/opt/miniconda/envs/pdal-python

1. Create a conda environment using conda create -n pdal -c conda-forge gdal ninja cmake cxx-compiler laszip pdal python-pdal pandas geopandas

2. Check the version of PDAL installed pdal --version and download the corresponding version from the PDAL current release.

   Example commands in linux:

   $ wget https://github.com/PDAL/PDAL/releases/download/2.5.5/PDAL-2.5.5-src.tar.bz2
   $ tar -xf PDAL-2.5.5-src.tar.gz
   

3. Download the rivlib-2_5_10-x86_64-linux-gcc9.zip (make sure to get the gcc9 version) and the the rdblib-2.4.0-x86_64-linux.tar.gz from the memebers area of the RIEGL website.

   • Unzip rivlib-2_5_10-x86_64-linux-gcc9.zip and add an environmental variable to point at the directory export RiVLib_DIR=/path/to/rivlib-2_5_10-x86_64-linux-gcc9.
   • Untar rdblib-2.4.0-x86_64-linux.tar.gz and add an environmental variable to point at the directory export rdb_DIR=/path/to/rdblib-2.4.0-x86_64-linux/interface/cpp

4. Before running cmake

   • edit line 58 of cmake/options.cmake to "Choose if RiVLib support should be built" True)
   • edit line 63 of cmake/options.cmake to "Choose if rdblib support should be built" True)
   • edit line 56 of plugins/rxp/io/RxpReader.hpp to const bool DEFAULT_SYNC_TO_PPS = false;

   Then, follow the PDAL Unix Compilation notes to compile PDAL. Example commands in Linux:

   $ cd /path/to/PDAL-2.5.5-src
   $ mkdir build
   $ cd build
   $ cmake -G Ninja ..
   $ ninja
   $ ls bin/pdal
   bin/pdal
   

   Next, add the this bin path to the environmental variable $PATH export PATH=/path/to/PDAL-2.5.5-src/build/bin:$PATH

5. cp build/lib/libpdal_plugin_reader_*.so /path/to/.conda/envs/pdal/lib/., this is required to open .rxp and .rdbx in Python.

Processing data

conda activate pdal

Create a direcotry in the the .riproject directory called extraction using mkdir, navigate into it and create a directoty called rxp2ply and navigate into this.

0. Download the python scripts from github

$ git clone https://github.com/philwilkes/rxp-pipeline.git

1. rxp2ply.py

Navigate to cd /path/to/xx.riporject/extraction/rxp2ply/ Run python /path/to/rxp-pipeline/rxp2ply.py --project ../../../xx.riproject --deviation 15 --odir . --verbose

This will populate the rxp2ply directory with full resolution tiled data

2. downsample.py

This downsamples the data to a uniform density

mkdir ../downsample and navigate to cd ../downsample

python /path/to/rxp-pipeline/downsample.py -i ../rxp2ply/ --length .02 --verbose

3. tile_index.py

Navigate back to extraction

python /path/to/rxp-pipeline/tile_index.py -i downsample where downsample is the directory with downsampled tiles.

4. Run TLS2trees

Instructions on this are here.