Process the Data

Create and Process a Project Tutorial

When you process LiDAR raw data, you can choose to extract an orthophoto, a DSM/DEM, buildings, trees, power line data, classified point clouds, DEM contours, and a terrain TIN.

Tip: Before processing the data, it is recommended that you generate a density map to check the point density of the LiDAR raw data. The more points per square meter, the more accurately ENVI LiDAR can identify landscape features and avoid false readings. When creating a DEM from low denisty data that has areas with no returns use the Variable Sensitivity Algorithm under the DEM Advanced Parameters for better results.

Click the Process Data button on the toolbar, or select Process > Process Data from the menu bar to open the Project Properties dialog. In this dialog you set the parameters for processing, preview the results of those settings in a subset of your data, modify the settings if needed, and process the data to create output (products). If you changed parameter settings and want to reset them to their default values, click the Reset Defaults button.

The Project Properties dialog is divided into three tabs, which are described in the following:

• Outputs tab: Select the product types to produce.
• Area Definition tab: Select the area of data to process (all data, or a subset).
• Production Parameters tab: Set parameters to produce the desired output.

When the parameters in the Outputs, Area Definition, and Production Parameters tabs are set, click one of the following buttons:

• Save and Close: Saves the settings and closes the dialog. Clicking this button does not process the data, but saves the settings with this project so that you can process the data later. To save the settings as a template that can be used with other projects, see Save and Use the Project Settings as a Template.

• Save and Preview: Saves the settings and shows a preview of the products that will be generated in the Main window. ENVI LiDAR creates a preview by processing the area that is selected in the Navigate window bounding box. Preview does not create output files.

  Depending on your needs for working with the LiDAR data, you can:

  • Select a different area in the Navigate window to create a preview using the current settings
  • Change the parameter settings and preview the same area again
  • Click Start Processing to perform full processing on the area selected in the Area Definition tab and generate output.

• Start Processing: Saves the settings and processes the data using the current settings and creates product output. The default location for the output is the \Products directory, under the project directory.

  Processing time varies based on the computer hardware, area size, point density, and the number of landscape features. You can monitor the progress in the Navigate window and in the Operations Log. Multi-core PCs will show several blocks being processed in parallel.

  To stop processing before it completes, select Process > Stop Processing from the menu bar. Processing does not stop immediately, but allows each process on each CPU to complete. The project is left in an "incomplete" state.