Requires an LP360 Geospatial Standard or above, LP360 Drone or LP360 Land Standard.

This Reproject LAS Point Cloud Task transforms the LAS points from one Coordinate Reference System (CRS), aka Spatial Reference System (SRS), to another. A useful when delivering data in a CRS different from the project CRS.

The task will take the original LAS and reproject it to a new CRS. This means that it can change any component of the horizontal datum, the vertical datum, the projection and the epoch.

It is a very powerful tool, since it allows users to transform an LAS and provides total control over it. Remember that LP360 can transform datums, something very few other software offers.

Figure 1: Reproject LAS PCT settings

Settings

Convert Coordinate Reference System: Checkbox to toggle on/off the option to reproject.

Output CRS: If Convert Coordinate Reference System is enabled, press the ellipsis to open the Coordinate System Utility dialog and select the CRS for the output LAS.

Source Epoch: refers to the specific time reference associated with the coordinate reference system (CRS) of the input LAS Layer to be reprojected. It defines the temporal context of the spatial data, which is especially important when working with time-dependent datums like NAD83(2011). This ensures that transformations between coordinate systems are accurate over time. In LP360, the source epoch should typically be the Project Epoch when reprojecting your project data to another CRS. 

Target Epoch: refers to the specific time reference associated with the coordinate reference system (CRS) of the output LAS Layer resulting from the reprojection. This will typically be automatically set to the default epoch for the output CRS.  Note: If the epoch is not selected automatically, set it manually.

• If you are trying to change the horizontal datum, for example, from WGS84 to NAD83(2011) make sure to select the correct epochs for each datum.
• If you are trying just to reproject a LAS, and not to change the horizontal datum, for example, from NAD83(2011) Alabama East to NAD83(2011) Alabama West, then, make set both epochs the same, i.e. 2010.0.

Apply Custom Geoid: Select a custom geoid in GeoTiff format. Note: Many common vertical datums are supported in LP360 with their various supported geoids. Select those in the Convert Coordinate Reference System, instead of here.

Output Folder: The location where the reprojected LAS will be saved.

Maintain Source File Structure: Enable to keep the file structure of the source (recommended), or create a single LAS output.

Write GeoTiff Tags: Writes the coordinate system GeoTIFF tags, as required in LAS v1.3 format or lower. LAS v1.4 requires a WKT and later revisions of the specification enforce no GeoTIFF tags in v1.4 PDRF 6 files.

How to Reproject LAS Files

1. Open LP360
2. Import a LAS.
3. Save the project --> Select the Project CRS which should match with the input LAS CRS.
   

   Note: When a new project is created, LP360 attempts to set the CRS of the project using the first loaded LAS file. If this can not be done (for example, there are many LAS files with no defined CRS), the user should set one in 'Project Settings' (Use Project CRS) in order for the Reproject to work correctly. In this case, the CRS set in the Project Settings dialog will always be used, regardless of the CRS of the Active LAS Layer.

4. Check the Project CRS, it should have horizontal and vertical datum.
5. Check the Source LAS CRS --> Right click on the layer --> LAS File Analyst -->SRS column --> Check also the LAS version and PDRF
   
   Tip: Recommended to always work with LAS 1.4 with PDRF 7 or higher. If you have an older format, you can update it using the Export Wizard .
6. If the Source LAS does not have a CRS --> Right click on the layer --> Set layer SRS.
7. Go to PCT --> Select 011 - TrueView - Reproject LAS.
8.  Select as output CRS (target CRS) and select the vertical datum.
   
9. Select the epoch if is not filled automatically. Select it manually.
10. Select an output folder to save the new LAS.
11. Perform the reprojection by running the PCT.