LAZ Processing

This workflow is intended for customers who want to process data not collected using Phoenix hardware. Users can import any LAZ file to perform various classification routines, create vector and raster products, and perform measurements or other analysis. If a trajectory file is loaded, users can perform strip alignment routines such as sensor calibration or trajectory optimization using LiDARSnap.

1. Open the SpatialExplorer (SE), select a CRS at the top right of the SE window, and save the project.

2. Use File->Open to open your LAZ/LAS file. Ensure that the LAZ fields are assigned correctly. If you indicate that the time format is Time of Week (TOW), SpatialExplorer will prompt you to specify the week that the data acquisition occurred. Once all fields are completed in the LAZ Import dialog, SE will create a CLOUD file, which will be used for processing. After processing the user can elect to export an LAZ/LAS again.

It is particularly important to correctly assign the time format of the LAZ. This is required to run LiDARSnap. If you don't know the time format of the LAZ, you can use the LAZ Importer to Scan Las Attributes. Typically time values that have 6 digits are Time of Week (TOW) format; 9 digit values are likely GPS Standard Time (Adjusted); 10 digit time values could be GPS Standard Time; time values with more than 10 digits could be GPS Microseconds.

3. Import a trajectory and run LiDARSnap (optional)

   1. Import your trajectory. NovAtel format trajectories (CTS/CLS) can be imported, as can SBET and POF/POFX trajectories.

   2. Create processing Intervals along the trajectory. Aerial flights can use the Create Intervals tool. With mobile lidar data, it's usually best to manually make a single interval covering the entire project.

   3. Specify an IMU orientation in the Project window. If you aren't sure of the IMU orientation, it's acceptable to leave as the default X: 0, Y: 0, Z: 0. IMU type can also be left as default.

   4. This is a good point to save the project using File->Save.

   5. Run the Compute SOCS tool. Compute SOCS is used to assign a pointcloud to a trajectory and recompute the raw lidar range and scan angle values from the world positions contained in the LAZ file.

      1. Make sure the correct pointcloud and trajectory are visible in the Compute SOCS window.

      2. Use the Add Sensor button to add a sensor model. Select your lidar model from the list - if it is not available, select Generic LAZ.

      3. Specify lidar to IMU transforms. If transform values are small, it may not be necessary to specify transforms when performing trajectory optimization. With sensor calibration, it is highly recommended to accurately specify transforms.

   6. Run LiDARSnap to perform strip alignment. Consider importing ground control points prior to running LiDARSnap.

4. Run automated classification tools, manual classification, or use the Analytics toolbar to create vector/raster products.