The Process LIDAR command provides numerous advanced LIDAR processing tools, including point cloud classification filtering, extraction of buildings and other structures, speedier surface generation, and much more.
- Processing of point cloud files
- Advanced filtering options to efficiently remove erroneous or unneeded points
- Merging multiple LIDAR data sets
- Trimming LIDAR data
- Thinning LIDAR data
To use the Process LIDAR command, the user must have already loaded the LIDAR data into the project. Refer to this knowledge base article on how to load an elevation layer.
Follow these steps to process the LIDAR data:
- From the Terrain ribbon menu, select the Process LIDAR command.
- The Process LIDAR dialog box will be displayed.
The following sections describe the Process LIDAR command and how to interact with the above dialog box.
Select LIDAR Layer to Process
This section controls the selection of the specific LIDAR layer to be processed from the available LIDAR layers contained within the project.
From the Existing LIDAR layer entry, select the LIDAR elevation layer that needs to be processed. Upon selecting the LIDAR elevation layer, the software will display the number of points contained in the LIDAR layer as well as the layer’s corresponding coordinate reference system (CRS).
Merge LIDAR Data
This section allows the user to select additional LIDAR layers to include and merge into the exported LIDAR file.
Trim LIDAR Data
This section allows the user to trim down the extents of the exported LIDAR file. There are two methods for defining the data extents from the Map View.
- User-defined limits: The user can define the limits for the LIDAR data to be exported. Click the [Pick] button. The dialog box will temporarily disappear, and a message will be displayed to the user on the status line. Click and drag a rectangular region to define the LIDAR data limits. After releasing the mouse, the user will be returned to the dialog box. A layer will be created with a rectangular box to represent the selected user-defined region.
- Model extents: If a project model has been defined, this option will create a bounding rectangular region to the extents of the defined model, plus an additional buffer boundary.
Filter LIDAR Data
This section is used to filter the LIDAR data based upon each LIDAR’s point classification. By default, the filter is set to filter everything out except for Ground (i.e., Bare Earth). The American Society for Photogrammetry and Remote Sensing (ASPRS) has defined a list of classification codes for LIDAR. Example classes include:
- Vegetation (low, medium and high)
A point can be classified into more than one category.
Thin LIDAR Data
This section is used for thinning large data sets.
Point clouds and LIDAR data sets can contain billions and billions of points. Many of the points are redundant and do not add any additional definition to the surface or object that they are describing. Also, loading large data sets can severely slow down your computer as it labors to load the data into memory. The thinning options provided by the software function to remove redundant LIDAR points.
Processed LIDAR Specifications
This section describes how to save LIDAR data after it has been processed.
Click the […] button for the Processed LIDAR file entry to specify the directory location to save the processed LIDAR file.
Processing the LIDAR Data
After the options have been defined, click the [OK] button, and the software will process the LIDAR data and save it as a new LIDAR file.
In addition, after the LIDAR data has been processed, the software can then load this LIDAR data as a new layer in the Map Data Layers panel.