Every lidar point can have a classification code assigned to it that defines the type of object that has reflected the laser pulse. You can classify lidar points into a number of categories, including bare earth or ground, top of canopy, and water. The classes are defined using numeric integer codes in the .las or .zlas files.
Lidar points stored in .las files are typically classified into categories using specialized classification tools outside of ArcGIS Pro. This classification is usually completed by setting parameters based on the terrain and then running algorithms on the point cloud to determine the feature type associated with each point. The classification code assigned to each point is written to the LAS file and, in most cases, adheres to the American Society for Photogrammetry and Remote Sensing (ASPRS) standard.
The list below includes common examples of how you can benefit from editing LAS automatically:
- Fix errors in class codes.
- Classify lidar points using GIS features.
- Change all classification codes currently in the LAS dataset.
- Classify specific features.
- Add or remove .las or .zlas files from a LAS dataset to increase or decrease the data area extent.
Geoprocessing tools for classification editing
Geoprocessing tools allow you to automate editing of classification codes.
| Geoprocessing tool | Description |
|---|---|
| Classify LAS Ground | Classifies unclassified LAS points into ground points. |
| Classify LAS Building | Classifies building rooftop points in aerial lidar data. |
| Classify LAS By Height | Reclassifies lidar points based on their height from the ground surface. |
| Set LAS Class Codes Using Features | Changes lidar classification codes assigned to lidar points based on their proximity to feature data. For example, you can use breaklines representing water boundaries to classify all points within the water boundaries as class code 9 to represent water. |
| Set LAS Class Codes Using Raster | Classifies LAS points using cell values from a raster dataset. |
| Locate LAS Points By Proximity |
Identifies lidar points within the three-dimensional proximity of z-enabled features while also providing the option to reclassify the points and export them to an output feature class. |
| Change LAS Class Codes |
Modifies the classification codes for LAS files referenced by a LAS dataset. This tool reclassifies one set of classification codes into another, which is particularly useful for updating the classification of LAS files generated before the introduction of classification standards in the LAS 1.1 specification. You can use the tool to ensure that such data conforms to the current standards. |
Classifies LAS points from overlapping scans of aerial lidar surveys. | |
| Classifies LAS points with anomalous spatial characteristics as noise. |