The following may be useful: GSD Calculator link
https://support.pix4d.com/hc/en-us/articles/202560249#gsc.tab=0
Can you share the intended use of the ground without having to come back and kill us once we know?
https://support.pix4d.com/hc/en-us/articles/202560249#gsc.tab=0
Can you share the intended use of the ground without having to come back and kill us once we know?