how about hanging metal detector from a drone or just plain autonomous RC car. I think once such massive de-mining starts in Ukraine, the tech would trickle down into archaeology and the like fields.
flemhans
Mount the equipment on the plows that anyway traverse the fields
CrazyStat
Most farmers would probably not want to stop plowing to check out whatever the detector pings on.
flemhans
Using a decentralized mesh network, the units could publish findings in a blockchain for treasure hunters to asynchronously react on.