Hi I've made up a stencil for 12 bit circular GCPs with a 54cm outer diameter. I have a Phantom 4 pro and a Phantom 4 multispec, and use both drones to survey agricultural field trials.
I'm wondering if anyone can tell me how to optimise the tolerance value in the auto detection menu of Metashape pro? I can't seem to find any documentation on this, but assume it's a function of the GSD?
The altitude with which we fly is generally between 20m and 40m, meaning the GSD of the P4pro falls between 0.55 and 1.1cm, whilst the P4m GSD is between 1.05 and 2.10cm.. I've attached a picture of the test GCP i made up, obviously purple isn't ideal, but Agisoft didn't seem to have troubles detecting it with the P4Pro, haven't finished aligning the multispec to test whether it works on that yet though..