Lidar (light detection and ranging) is an optical remote-sensing technique that uses laser light to densely sample the surface of the earth, producing highly accurate x,y,z measurements. Lidar, primarily used in airborne laser mapping applications, is emerging as a cost-effective alternative to traditional surveying techniques such as photogrammetry. Lidar produces mass point cloud datasets that can be managed, visualized, analyzed, and shared using ArcGIS.
ArcGIS Pro supports lidar data provided as LAS or Optimized LAS (.ZLAS) files. There are different formats (datasets) that can be used to manage and work with your lidar data in ArcGIS Pro depending on your needs, which include the LAS dataset, the mosaic dataset, and the point cloud scene layer. Also, individual LAS or ZLAS files can be used in ArcGIS Pro with the same support as a LAS dataset.
Note:
You cannot conduct any edits on a ZLAS file. You would have to decompress the ZLAS file back to a LAS file to complete any edits on the points.
When a LAS dataset, LAS or ZLAS file is added to a 3D scene in ArcGIS Pro the points are symbolized with an elevation renderer and eye-dome lighting applied, by default. Eye-dome lighting is a shading technique that improves the perception of depth and contour when viewing LAS datasets.
The following table compares lidar support in ArcGIS using a LAS dataset or LAS file, mosaic dataset, and a point cloud scene layer.
Data types that support lidar data
| LAS dataset or LAS File | Mosaic dataset | Point cloud scene layer | |
|---|---|---|---|
ArcGIS applications | ArcCatalog, ArcScene, ArcMap, and ArcGIS Pro | ArcCatalog, ArcGlobe, ArcMap, and ArcGIS Pro | ArcGIS Pro |
Storage locations | File system | Geodatabase | Scene layer package |
Relationship to LAS source files | Points to | Points to | Builds a cache |
Size limitation | Limited by space on disk | Limited by size allowed by geodatabase | Limited by space on disk |
Surface constraints | Supported | Not supported directly (supported if present in LAS dataset or terrain dataset) | Not supported |
Lidar inputs | LAS files, ZLAS files | LAS files, terrain datasets, LAS datasets | LAS dataset |
Types of lidar | Airborne and terrestrial | Airborne | Airborne and terrestrial |
Rendering | Points, triangulated surface viewed in 2D and 3D | Raster | Points viewed in 3D |
Analysis | Tools that can ingest point clouds or TINs. Use with 3D Analyst tools. Use with LAS dataset tools. | Use with tools that can ingest raster data. Use with Spatial Analyst tools and other raster dataset tools. | Not supported |
Display | Thinned points. Can change display by choosing different class types or data types. Display is modified by changing the symbology and/or point filters. | Uses cache for faster display. Can change display by choosing different class types or data types. Display is modified using the Layer Properties dialog box or the Image Analysis window. | Thinned points. Uses cache for faster display. Display is modified by changing the symbology and/or point filters. |
Editing points | Can edit the point classification residing in the LAS files | Cannot edit points | Cannot edit points |
Combining with data | Supports LAS files, feature classes, and shapefiles | Supports LAS files, LAS datasets, terrain datasets, and other raster formats | Supports LAS datasets |
Use an individual LAS or ZLAS file
An individual LAS or ZLAS file can be used in ArcGIS Pro, which allows you to examine a LAS or ZLAS file quickly without creating a LAS dataset. This functionality allows you to understand the data before using the file as input into another dataset. LAS and ZLAS files behave in the same way as a LAS dataset in ArcGIS Pro.
LAS and ZLAS file can be utilized as follows:
- Displayed in 2D or 3D as points using elevation or point attribute renderers based on certain lidar filters applied to the point cloud
- Rendered as a triangulated surface model (TIN)
- Visualized using elevation, slope, aspect, or contour lines based on certain lidar filters
- Used as input to many 3D Analyst analysis tools
- Have the point classification edited
Use lidar as a LAS dataset
The LAS dataset provides fast access to large volumes of lidar and surface data without the need for data conversion or importing. You can work with several thousand LAS files covering an entire administrative area or perhaps just a few LAS files for a specific study area. It allows you to examine LAS or ZLAS files quickly, providing detailed statistics and area coverage of the lidar data in the LAS or ZLAS files.
A LAS dataset can be utilized as follows:
- Displayed in 2D or 3D as points using elevation or point attribute renderers based on certain lidar filters applied to the point cloud
- Rendered as a triangulated surface model
- Visualized using elevation, slope, aspect, or contour lines based on certain lidar filters
- Used as input to many 3D Analyst analysis tools
- Have the point classification edited
Edit LAS files
LAS datasets can be edited to make updates to the classification in the source LAS files or surface constraints contributing to the surface model. Editing the point classification in ZLAS files is currently not supported.
Use lidar in a mosaic dataset
By adding your lidar data to a mosaic dataset, it can be used and rendered as a raster. This allows you to do the following:
- Use tools such as Viewshed, Contour, and Profile.
- Estimate volumes.
- Use it as a DEM.
- Use it to orthorectify imagery.
- Use it in applications that support rasters but not LAS files or LAS datasets.
The mosaic dataset is similar to the LAS dataset, in that it stores a pointer to the original dataset and does not move all the points from one format into another; therefore, it is quick to create, small in file size, and easy to update with additional LAS files. Alternatively, you can convert your LAS files or LAS dataset to a raster dataset.
You can also use a mosaic dataset to catalog all your lidar data.
Share lidar data using a point cloud scene layer
Point cloud scene layer provide fast display of large volumes of symbolized and filtered point cloud data. They are optimized for the display and sharing of many kinds of sensor data, including lidar. A point cloud scene layer can be published as a service layer and uploaded to Portal for ArcGIS or ArcGIS Online using the Share Package geoprocessing tool.