Add Ground Control Points (GCPs) to the Point Cloud

After your reprojection is finished, it is time to add GCPs to LiDAR data with the ROCK Cloud

GCP Best Practices

To learn more about best practices for materials to use, target size, shooting in the GCP, see article here: GCP Best Practices

Wait to load your GCPs until after your reprojection process has completed to prevent coordinate errors.

Using a Known Coordinate Reference System For GCPs

The datum that will default for your GCPs is the Defined Coordinate Reference System (CRS) you set during project setup. If you set a project reprojection than that CRS will be the default datum for your GCPs. To learn more about reprojecting your project see: Reprojecting your ROCK Project

  • Select Add Ground Control Points Menu under Manage Project.
    Screen Shot 2022-04-21 at 2.36.12 PM

Option 1: Individual GCP Input

    • Enter the Title, X, Y, and Z of each control point for your project.
    Screen Shot 2022-04-21 at 2.40.43 PM
  • Select the "Projection" that your GCPs were captured in.

Your GCP Projection should ideally be the same as your Reprojection (AKA Final Projection)

  • Click save.
  • Wait for your GCPs to process and the green GCP pins to populate in the map and LiDAR viewers.

Option 2: Uploading Your GCPS with a CSV File

  • Select the Upload CSV button at the top.

    Screen Shot 2022-04-21 at 2.41.08 PM
  • Click "choose file" and then select the control file you'd like uploaded.

The formatting of your CSV is VERY important. Make sure your file format is CSV, comma delimited, and your header is formatted as noted in the popup without any excess columns or rows. Any deviations and the file cannot be read and used until you reformat.

  • Spot check your coordinate data imported.
  • Click Save.
  • Wait for your GCPs to process and the green GCP pins to populate in the map and LiDAR viewers.

Using a Custom Coordinate System

Custom Coordinates are arbitrary points within a known CRS.  For example, within Texas North Central State Plan you want to shift your project to 1,000 1,000 500 x,y,z coordinates.


  • Click "Show Advanced"
    Screen Shot 2022-04-21 at 2.58.03 PM
  • Key in the custom coordinates of at least four known points.
    Screen Shot 2022-04-21 at 2.54.52 PM

For these translation points you will need to have the coordinate in both, the known CRS, AND the arbitrary system so our system can build the translation for the project. (The two above screenshots show a "known" xyz and the custom xyz keyed in. 

 

Use the navigation menu below to continue the tutorial.

ROCK Cloud Tutorial

Reproject the Data

ROCK Cloud Tutorial

Align Project to GCP's