Idea on maximizing relic hunting

[Canewrap]

With a shrinking pool of productive old sites to hunt, has it ever occurred to anyone to plant a target for calibration purposes at a site they've been hunting for a while and might be hunting for a while yet? Seems to me that if you have a known target at a specific depth, in ground you're hunting, it's easier to tell how to adjust your machine to get the optimal results for that specific ground. Yes, it will take a bit for that target to reflect true conditions as the soil density will have to re-establish itself. However, if you burrow into the side wall of the hole and push the target into the dirt, instead of just dumping it at the bottom, it will give a truer reading faster. Anway, just a thought I would share on how we might be able to squeeze just a few more targets out of hard worked areas.