I saw Massoud Hassani on the internet and he has made a landmine detecting drone which can fly to a grid pattern If in the future a metal detecting company collaborated with him to make a metal detecting drone then you could site back and wait as the drone flies up and down the field GPS marking the targets. You could cover a field in hours rather than weeks!
I would call it the ‘Hoard Hunter’
https://www.kickstarter.com/projects/massoudhassani/mine-kafon-drone?token=4a3c87bf
I would call it the ‘Hoard Hunter’
https://www.kickstarter.com/projects/massoudhassani/mine-kafon-drone?token=4a3c87bf