We’re having some issues with processing on sites with grid to ground scale factors applied to state plane coordinate systems. The plan scale factor results in roughly a 90 ft shift from state plan coordinates. This is causing the AutoGCP function to not work since I assume the initial GCP position is too far away. Is there any way to handle coordinate systems with scale factors applied to them? What is the tolerance for the AutoGCP function to work?
Hello @survey11
We are happy to help you. We would like you to clarify the following aspects:
a) What do you mean by “grid to ground scale”?
b) Why do you need to apply a scale factor in your project?
Please explain in detail what you need to clarify.
Regarding the AutoGCP tolerance, GCPs must be localizable by the AutoGCP algorithm within a maximum range of 5 x 5 meters in the x- and y-axis of the coordinates referenced in the CSV file for each one. Large inaccuracies in the coordinates referenced in the CSV or in the images’ geotags can influence the algorithm’s search range, leading to failure in automatic GCP detection. There are more details about this topic in the following article, AutoGCPs detection functionality - PIX4Dcloud Advanced.
I am looking forward to your answer.
Best regards.