Support Website Contact Support Blog

Quality Report BUG - Wrong GCP Error values

I consistently find this error in the quality report or in the params files, in which the geolocation errors for the GCPs in the quality report are different from the errors calculated between estimated and measured coordinates.

For instance, I open the file in: ...\my_project\1_initial\params\my_project_measured_estimated_gcps_position.txt.

This file contains the measured coordinates for control points and also the estimated coordinates. The values are consistent with the measured coodinates I have input. The values are also consistent with the files my_project_estimated_gcps_position.txt and my_project_measured_gcps_position.txt.

Then I put these values in a spreadsheet and calculate the errors:
(I removed the initial digits of X and Y to protect the information)

Now, when I look at the quality report, I get this table (in which I inserted the checkpoints in the middle to make a single table).

image

Notice how all the “checkpoints” contain exactly the same error. However, the GCPs have big (and inconsistent) differences. Look at the highlighted cell in orange and compare to the others.

Below, the difference between the errors I calculated and the errors presented in the report:

image

What is going on here? Is Pix4D bugged for GPC errors?
What is wrong? The files? The quality report?

Pix4D Mapper Version: 4.5.6