# Corrections
The Corrections window stores computed corrections, and enables users to apply rigid adjustments to the trajectory and pointcloud. The [Align to GCP](https://docs.phoenixlidar.com/spatialexplorer-8-and-9/user-interface/toolbars/workflow/ground-control) 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 ](https://docs.phoenixlidar.com/spatialexplorer-8-and-9/user-interface/toolbars/workflow/ground-control)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:
{% hint style="warning" %}
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.
{% endhint %}
Use the **Import from Measurements** button to import the measurements as either a Vertical, Horizontal, or Full correction:
{% hint style="info" %}
If you intend to run LiDARSnap with manual corrections enabled, the correction must be a Full (i.e. horizontal and vertical) correction.
{% endhint %}
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
{% hint style="warning" %}
If you are creating corrections to be used with LiDARSnap, do not attempt to apply corrections, as discussed below. For LiDARSnap, Full corrections should be present in the corrections window.
{% endhint %}
Corrections can be applied to the active trajectory. This is useful when a single, global shift of the data set is required. 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.
