Model with GCP gets mirrored

[Sky_hie]

Hello.

I am making a 3d model based on UAV images and With GCP from a Trimble Rover GPS. When adding gcp data, I choose "marker accuracy =0"

When I do this the model gets mirrored. If I chose value: 0.005, the model is the right way.

Why is this happening and what is the recommended value here..?


SH