Corrections

The Corrections window stores computed corrections, and enables users to apply rigid adjustments to the trajectory and pointcloud. The Align to GCP tool automatically creates vertical corrections in the Corrections window, however corrections can also be created manually from measurements:

Creating Automated Vertical Corrections

Use the Align to GCPs tool to create corrections from vertical residuals between GCPs and the pointcloud:

Creating Corrections Manually

Corrections can also be created manually by selecting points or GCPs in the main view (creating measurements) and then using the Import from Measurements tool.

To create corrections manually, select a GCP and the corresponding point in the point cloud which should be co-located with the GCP:

You should then have two entries in the measurement window, one with source (SRC) PointCloud, and one with source GroundControl:

Keep the Measurements window clean! A correction must be between two points, either one GCP and one pointcloud point, or two points in the pointcloud. If your measurements window has more than two entries, a correction cannot be created.

Use the Import from Measurements button to import the measurements as either a Vertical, Horizontal, or Full correction:

If you intend to run LiDARSnap with manual corrections enabled, the correction must be a Full (i.e. horizontal and vertical) correction.

After creating the correction, you should see it as an entry in the Corrections window, as well as visualized in the main view:

A correction can also be created from two points in the pointcloud, or between two points in two different pointclouds. To create a correction from two pointcloud points, disable the GCP-point corrections option:

Applying Corrections

Corrections can be applied to the active trajectory. Corrections are averaged amongst type, meaning that all vertical corrections are averaged to determine a single vertical adjustment, and all horizontal corrections are averaged to obtain a single horizontal shift:

Applying a correction to the active trajectory will create a new trajectory with the applied shift.