Presenters

  • Liam A.K. Irwin - PhD Student
  • Brent A. Murray - PhD Student
  • Sadie Russel - PhD Student
  • Nicholas C. Coops - Professor

Integrated Remote Sensing Studio University of British Columbia Vancouver, Canada

Overview

  • Light Detection and Ranging (lidar)
  • Introduction to the lidR package
  • Introduction to LAStools
  • Workshop outline

What is lidar?

  • Light Detection and Ranging
  • Active form of remote sensing
  • Measures distance to target surfaces with millions of narrow light pulses
  • Airborne laser scanning performs lidar systematically from aircraft or drones

Lidar Data – Point Clouds

  • Discrete returns are aggregated into point clouds (.LAS/.LAZ)
  • Lidar points have three-dimensional (XYZ) coordinates, and other attributes (Intensity, ReturnNumber, etc…)
  • Point clouds can be processed into vegetation structure summaries with lidR

lidR

  • Written by Jean-Romain Roussel
  • Package for manipulating and visualizing ALS data
  • Written entirely open source within R-geospatial ecosystem (terra/sf)
  • Most processes run efficiently with back-end C++ code

LAStools

  • Industry grade software suite produced by rapidlasso
  • 52 command-line tools for mutlicore batch processing lidar data
  • More memory efficient than lidR (doesn’t load as dataframe)
  • Some tools required paid license

r-lidar

  • lidR author Jean-Romain Roussel is commited to maintaining the lidR package as fully open source
  • He now runs r-lidar; a consulting and development company targeted at lidar applications
  • Visit r-lidar.com for more information

Workshop Outline

  • Introduction to Lidar, LAStools, and lidR (09:00)
  • Preprocessing with LAStools (9:20)
  • Reading LAS and LAZ files (09:30)
  • Point Classification and filtering (9:35)
  • Digital Terrain Models and Height Normalization (9:40)
  • Canopy Height Models (9:50)
  • Lidar Summary Metrics (9:55)
  • Break (10:15-10:45)
  • File Collection Processing Engine (10:45)
  • Regions of Interest (11:0)
  • Area Based Approach (11:10)
  • Individual Tree Detection and Segmentation (11:30)
  • Questions (11:50)

Get Set Up!

https://liamirwin.github.io/SL25_lidRtutorial/