🤗4.2 Collaborative Mark GCPs Tutorial

Ground Control Points (GCPs) are precisely surveyed reference points strategically deployed within your area of interest using ground targets to enhance the geospatial (absolute) accuracy of aerial maps. GCPs provide ground truth coordinates, acting as anchor points for Drone's photogrammetry process.

Get3D Mapper supports multiple Mark GCPs, i.e., for a large number of control points in a real project, it supports multiple computers to Mark GCPs together to enhance work efficiency.

The logic is that Get3D Mapper supports opening sub-projects on multiple computers, and the only operation that sub-projects can do is to edit control points.

When the main project enters the interface of editing control points, it locks all control points by default.

When the main project releases a portion of the control points, the secondary project can lock that portion of the released control points and perform Mark GCPs operations. When multiple computers have finished collaborating on the marking, click on each computer to save the control point information.

Finally, the main project will update the control point information.

The specific operation is as follows, in the main project in the submit aerial triangulation interface click Edit Control Points to enter the Edit Control Points interface. Import the control point file and select the correct coordinate system.

Select some control points and click Unlock.

Open the project on another computer, when you open it, the default prompt is that the project opened here is a sub-project, and you can only edit control point operations.

Enter the Edit Control Points screen, click "Update" to see the unlocked control points, and then you can Mark GCPs on the machine after locking it. When you are done, click "Save" and "Update".

After completing all marking point operations, click Save, Update in the main project to exit this screen.

The specific marking point operation is as follows:

Double click the selected control point, the right side display can see the photo of the point.

Click the right photo, the current photo enlargement will be displayed in the lower photo view interface.

Move the mouse to the correct position and click Shift to perform the marking operation.

Observe the relative Relative Re-projection Error and do not exceed the limit.

A control point usually needs to repeat the above operation 20-30 times.

When the marking operation is complete, click Save before exiting.