Module 05

Lidar & 3D visualization

Yesterday at Mammoth Cave
Webcam archive
GEO 409: Advanced GIS

What did you do over break?

  • 🎉🏀
  • 🎸🗺️
  • 🏖️🍹


Spring, finally!

  • Yesterday's animation from GEOS-16: GIF

Example lab 5

  • Corner of Limestone and Avenus of Champions: Esports Theater on University of Kentucky’s campus page

Pauer Cartography Award

  • Submissions are open!
  • Cash prize
  • Traditional cartography, 3D mapping, and web maps
  • Let me know if you want to submit.

Geography Enrichment Award

  • Want to explore a mapping and GIS topic in more detail?
  • Get paid to explore this topic!
  • Let me know if you if you are interested.


  • 3D visualizations.
  • Python to process data.
  • Final project theme?

Virtual field trip to

Chained Rock


Play 1-10 Chained Rock ⬇️


(Light Detection and Ranging)


  • Active sensor
  • with multiple returns and attributes.
  • Creates a point cloud (massively sampled locations).

Point cloud attributes

  • x, y, z position
  • time
  • intensity of return
  • Custom algorithms classify point

Airborne lidar

  • Massive sampling of earth's surface by plane.
  • Uses GPS and IMU (inertia measurement unit) to map point.
  • While can penetrate canopy, cannot 'see' under solid structures.
  • I.e., cannot see under our arches, bridges, overhangs.

Terrestrial lidar

  • Ground-based sampling.
  • Can build true 3D model, e.g., see under and inside.
  • Increasingly available in consumer products.

Airborne + Terrestrial 🤯

  • The most detailed model of our environment that has ever been made. Hi, digital twin!
  • Who's collecting data?
    • Your car, phone, computer, etc.
  • Benefits/problems
    • VR and AR experiences in real places.
    • You're 'known' more precisely.
    • Hey, your living room could fit this new chair!

Lidar challenge

  • Massive file size
  • State divided into 46,105 tiles
  • with one tile ~ 500 MB.
  • Difficult to visualize (today).
  • How to handle these file sizes?


  • Code most of the processing in ArcPy
  • to output raster derivatives
  • and browser optimized point clouds using video game technology.
9 GB point cloud > 250 MB raster


  • Abundant uses of lidar justify the technology
  • and our careful workflow.
  • What use might you discover?


  • The most detailed, comprehensive digital elevation model of our environment that has ever been made,
  • including underwater.
  • Flooding, landslides, geological hazards, etc.
  • Just look at the shaded relief maps you have already made.


  • New detail at archeological sites.
  • Lidar can penetrate dense canopy
  • and reveal details about past built environments.
  • Ancient Mayan cities



  • What can you do with a detailed model of a city?
  • Reduce greenhouse emissions?
  • Put solar panels on buildings with most insolation.
  • Sanborn lidar NYC

Kentucky project


  • Create high-resolution elevation products for bare-earth conditions.
  • A statewide 5-ft resolution DEM is now available.
  • Collected 2010–2021
  • Two phases show different times.
  • Completely free.


  • Algorithms classify point
  • Need to filter for ground points.
  • All (non-noise) points give us tree height


  • Heads-up digitizing to enforce hydro rule
    • Classify bridges and noise.
  • Field measurements to verify accuracy
    • Most measurements within .2 ft

Data location

  • LAS file format
    • Laser format most common in GIS
  • LAZ file format
    • A compressed LAS file
    • Most common storage format
    • Need a separate utility to decompress and use in ArcGIS Pro.
      • laszip.exe include in our tools folder

Data location


  • Create a folder in your root GIS folder called
    • lidar
  • In that folder, create a folder called
    • download
  • Download two adjacent tiles to that folder
    • Make sure they are the same Phase, i.e., same version.


  • Drag and drop the LAZ file, one by one, onto the laszip.exe application
  • Verify that you have two LAS files.

Create LAS dataset

  • Treat multiple tiles as a single layer.
  • Enter Python and the Lesson-05.ipynb

Point cloud Derivatives

Airborne point clouds can be reduced to high-resolution raster imagery.


  • Digital Elevation Model
  • Most often bare-earth surface
  • Point cloud class code 2


  • Digital Surface Model
  • Includes the reflected surface
    • buildings, trees, bridges, etc.
  • Point cloud class codes 1, 2, 9, 17


  • Digital Terrain Model
  • bare-earth surface
  • with vector features to model surface features
    • lines for streams, polygons for lakes, etc.
  • Point cloud class codes 2 and digitized features

Steps in model creation

  • Filter point cloud
  • Make LAS dataset layer (temporary)
  • Rasterize LAS dataset layer

Colorize point cloud

  • Apply color from overlapping imagery.
  • Can create realistic view of area of interest.
  • Creates new LAS files
    • Doubling your project size.

Load imagery

  • Connect Kentucky ArcGIS Server
  • Add server to new ArcGIS Pro projects

Explore 3D Kentucky

Application steps

  1. Start in lesson
  2. Run notebook to process data (a few times to practice)
  3. Start with a small buffer distance, e.g. < 1000 feet
  4. Design 3D map and animation


  1. to the world
  2. with an image and a video animation.
  3. Practice making a web page?