Displaying LAS LiDAR point clouds in the Whitebox map area

I enjoy working with LiDAR data whenever I can because of its remarkable topographic detail and unique characteristics. More often then not, I work with LiDAR data interpolated onto a raster grid. Lately, however, I’ve been working with terrestrial laser scanner data and having a means of quickly visualizing the point data itself has become important to my workflows. Did you know that as of the latest release of Whitebox GAT (v. 3.2.1) there is now native support for displaying LAS files, the commonly used standard format for storing LiDAR point clouds, in the map area?

Adding LAS layers to a map area

Adding LAS layers to a map area

The LAS point cloud will be added to the Whitebox map area in the same way that you can overlay other vector or raster geospatial data. Here’s an example of a LAS dataset overlaid on top of a raster hillshade image.

Example LAS point cloud

Example LAS point cloud (click to enlarge)

The display properties, including the point size, colour palette, and display value ranges can be easily manipulated.

LAS display properties

LAS display properties

You can even render the point cloud based on elevation, intensity, class value, scan angle, or the GPS time (This is a newly added feature that will be present in the next public release).

Rendering attribute options

Rendering attribute options

Here’s an example of a LAS point cloud rendered using its intensity data. It’s interesting how much it resembles a fine-resolution orthophotograph, but this image is actually made up of millions of individual points. You need to zoom in to see them all.

LAS file rendered by intensity

LAS file rendered by intensity (click to enlarge)

Visualizing the GPS time and scan angle can be very useful for identifying individual flight lines in airborne LiDAR datasets. Here’s an example of rendering the LAS file displayed above using the GPS time as the display attribute:

GPS time rendering

GPS time rendering (click to enlarge)

It may not be much to look at (unless you really like orange), but the edges of the various overlapping flight lines are quite apparent.

I’ve also recently added a new LiDAR Histogram tool that will allow you to visualize the statistical distribution of elevation, intensity, or scan angle within a LAS dataset, including outputting a table of the percentiles.

LiDAR histogram tool

LiDAR histogram tool (click to enlarge)

Whitebox has certainly become a first-rate open-source platform for manipulating and analyzing LiDAR data. And it’s getting better with every release! Leave your comments below and, as always, best wishes and happy geoprocessing.

If you enjoyed this blog, you may also enjoy “Working with LiDAR data in Whitebox GAT“.


3 thoughts on “Displaying LAS LiDAR point clouds in the Whitebox map area

  1. fionag11 says:

    1. What palette were you using with the scan angle example?

    2. Is there anyway to see the class legend ie when symbolized by class, what colour is what class?

    • Hi fionag11,

      1. The first image is rendered using the ‘spectrum’ palette in Whitebox and the intensity image is the ‘grey’ palette. 2. No currently there is no way to do that with the palette but I can certainly work to add that feature in a future version.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s