Obtaining LiDAR data from the USGS
Thanks to the USGS’s 3DEP (3D Elevation Program), it’s possible to download Lidar Point Cloud data for select (but growing) U.S. locations free of charge. This isn’t exactly new news, but it’s impressive to watch the coverage areas grow. My typical area of interest is now mostly covered.
- Go to The National Map Viewer application
- Turn on the Lidar point cloud layer to see the available data
- Somewhat buried under “Elevation Index - 3DEP” > “Source Data Index - Lidar, lfsar, DEM” > “Lidar Point Cloud”
- Then, I find it easiest to zoom in to the extent of interest, click the “Download Data” button in the upper right, select by either view extent or draw a new box.
- In the list of available data, check the box next to “Elevation Source Data” > Next
- Select one or more of the datasets (they’re rather large) > Next again
- Click “Checkout” and enter your email address. You’ll be emailed a download link shortly.
Convert that data to a multi-point feature in ArcGIS
The simplest method I’ve found for using these .las files in ArcGIS is as follows:
- Convert .las files to multipoint through ArcToolbox
- Use ArcToolbox again to define projection for the new multipoint - get the original coordinate system from the metadata text file of the lidar point cloud
Create a DEM in raster format
- Use ArcToolbox point to raster tool to create a raster elevation model. Use z value for cell value. Z value will be in meters. More info here