Exploring Lidar data

Before tackling this tutorial, you will need to download and install a dataset following these instructions:

Create a folder called lidar somewhere under your personal directory (e.g. C:\Users\jdoe\Documents\Tutorials\lidar\).
Download the data for this exercise then extract the contents of lidar.zip into your newly created lidar folder.

Open the GIS project

The project consists of an empty ArcGIS Pro project (except for the default background layer) and a LAZ data file covering parts of the Colby campus (currently not loaded in the map project). This sample dataset was extracted from the full lidar dataset originally downloaded from the USGS website. If you wish to work off of other lidar datasets, point your browser at https://apps.nationalmap.gov/downloader/.

ArcGIS Pro will work directly with LAS file formats but not with LAZ formats which is the format more commonly found on the internet. LAZ formats are simply a compressed version of the LAS file that can be converted in ArcGIS as outlined in the next step.

Converting LAZ to LAS

Under the Analysis tab, click on the Tools button.
In the Geoprocessing search bar, type convert las. This should bring up the Convert LAS tool in the search results.
Click on the Convert LAS tool to bring up its window.

Next to the Input LAS field, click on the folder icon, then select the Colby.laz dataset under the lidar project folder.
Click OK to accept the file.

Next to the Target Folder field, select the folder icon then select the lidar project folder. Make sure to select the lidar folder from the right pane in the Target Folder window. If you select it from under the Project folder in the left pane, the lidar folder will not be properly selected.
Click OK to accept the folder destination.

Do not make any changes to the other settings.
Click on Run to execute the geoprocess.

After the geoprocess completes, you should see a new Colby.las file appear in the lidar project folder.

Note that you might need to refresh the Catalog pane to see the newly created file. You can refresh the window by clicking the F5 key or by right-clicking the lidar folder and select Refresh.

Viewing the LAS data

Add the Colby.las file to the Map view (you can drag and drop the file from the Catalog window).

Note that the points will not be visible at all zoom levels. For example, if you zoom out to a scale of 1:10,000, the layer displays a red box that delineates the lidar point extent.

With the Colby.las file selected in the Contents pane, you will note the presence of a new LAS Dataset Layer tab.

The LAS ribbon offers many of the same visualization tools seen with vector datasets, but it adds an additional button, LAS Points, that allows the user to filter Lidar points by classification and return types.

In the next step, you limit the Lidar points to those associated with ground elevation.

Click on the LAS Points button in the LAS Dataset Layer ribbon and select Ground.

You should now see a subset of points. Note that the points representing building rooftops have been filtered out.

Feel free to explore other filters from the LAS Points pull-down menu.

Creating raster layers from LAS points

Next, you will create a raster layer of ground elevation from Lidar point data.

Restrict the Lidar point data to ground elevation following steps outlined in the last section.
Bring up the Geoprocessing window search bar and type las to raster. This should bring up the LAS Dataset to Raster tool in the search results window.
Click on the LAS Dataset To Raster tool to bring up its window.

Select Colby.las as the Input LAS Dataset.
Name the Output Raster ground.tif (make sure to save it in the lidar project folder).
Set the output pixel size to 1 meter in the Sampling Value field.

Note that you should be careful in choosing pixel sizes when working with large spatial extents. Given that the current extent is small, a 1 meter pixel size is manageable.

Click Run to execute the geoprocess.

You should now see a ground elevation raster layer in your current map window. Feel free to change its symbology following techniques highlighted in another tutorial.

Exploring Lidar data in 3D scene view

On the Insert ribbon, click on the New Map pull down menu and select New Local Scene.

In the Scene view, drag and drop the Colby.las file from the Catalog pane.

ArcGIS will automatically recognize the LAS datatype and add it to the 3D Layers group in the Contents pane.

Feel free to navigate the layer in 3D mode. For example, to tilt the scene, click and hold the middle mouse button while moving the mouse forward or backward.