An overview of editing LAS datasets

LAS datasets can be edited to make updates to the source LAS files or the lidar points in the source LAS files. LAS datasets can be edited to fix problems, make improvements, and increase or decrease the data area extent.

The list below includes common examples of how you can benefit from editing LAS datasets:

• Manually fix errors in class codes.
• Visually compare the lidar points against existing GIS data for data validation, such as building data.
• Classify lidar points using GIS features.
• Reclassify lidar points manually selecting one or many lidar points.
• Change entire classification codes currently in the LAS dataset.
• Add or remove LAS files from a LAS dataset to increase or decrease the data area extent.
• Add or remove other GIS surface features, known as surface constraints, to/from the LAS dataset.
• Interactively measure 3D distances between visible features, such as power lines and trees.
• Use the lidar points as backdrop data to digitize in new GIS features, such as street furniture.
• Assign a spatial reference to a project if necessary.

Editing a LAS dataset falls into two broad categories:

• Adding or removing LAS files or surface constraints referenced by the LAS dataset. For more information on editing the LAS files available in a LAS dataset, see Adding or removing LAS files.
• Edits or updates to the classification codes applied to the lidar points residing in the LAS files. For more information on editing the lidar point classification, see Editing LAS point classification codes.

Note:

Many tools for the LAS dataset were designed for airborne lidar where surfaces are commonly interpreted from the point cloud. Terrestrial lidar, on the other hand, tends to be more involved and is often only valid to view and use as a point cloud. ArcGIS does not understand what kind of lidar you have in the LAS files. Terrestrial lidar should be used and viewed in ArcScene as points. The points can be used as a backdrop for digitizing measurements and features and be displayed in an integrated fashion with other GIS layers.

LAS dataset editing examples

From the application perspective, there are some common editing needs:

Common LAS dataset editing tasks

Task	Example	ArcGIS support
Expanding area of coverage over time	Appending new measurements as they become available (Data acquisition is often staged over time with multiple data deliveries from a data provider.) Expanding the data extent	Use the Add Files To LAS Dataset geoprocessing tool.
Quality assurance	Identifying and removing errors Removing blunders representing individual measurements Replacing areas containing systemic errors with corrected measurements	Use the LAS Dataset Profile View window for interactive viewing, reclassifying points, and to flag points as withheld in the classification. Conduct statistics to ensure data quality. Use the Locate Outliers geoprocessing tool. Use either the Add Files To LAS Dataset or Remove Files From LAS Dataset geoprocessing tool to replace data.
Maintenance	Replacing areas with new or updated information (for example, changes to a landscape as a result of construction or natural forces) Replacing data with data of higher quality/accuracy	Use either the Add Files To LAS Dataset or Remove Files From LAS Dataset geoprocessing tool to replace data. Note: You can also use the LAS Dataset Properties window to add or remove LAS files or surface constraints from the LAS dataset.
What-if scenarios	Modeling proposed changes on the landscape Replacing existing measurements with new ones May be temporary or permanent	Convert a portion of the LAS dataset to a TIN and use the TIN Editing toolbar tools. Use either the Add Files To LAS Dataset or Remove Files From LAS Dataset geoprocessing tool to replace data. Note: You can also use the LAS Dataset Properties window to add or remove LAS files or surface constraints from the LAS dataset.