Point cloud data analysis

Topic 4B: GIS Analytics

Outline

• Compare lidar and UAS SfM point clouds: how each sensor samples the ground, the canopy, and buildings
• Read a LAS file: returns, intensity, classes, and the LAS format
• Analyze point distribution by binning: densities, vertical range, outliers, and the supported resolution
• Extract bare ground and thin a point cloud
• Compute DEMs and DSMs by binning, triangulation, and spline interpolation, with topographic parameters
• Analyze vertical structure with voxel models and transects

Lecture

• Lecture slides

Supplemental materials

• Processing point clouds in GRASS, workshop presented at FOSS4G conference in Boston in 2017 (start with the section “Binning the point cloud”).

• USGS 3DEP Data View

• LAS specification v1.4, maintained by ASPRS on GitHub (the PDF is under Releases)

• Mobile mapping with lidar: why is an INS essential, OXTS

• Past Lecture recordings:

  • Properties
  • Processing
  • DEMs and voxel models

Assignment & Homework

Assignment 4B