Used to hate ground-penetrating radar until I saw it catch a Roman road that 3 test pits missed

I always thought GPR was just expensive guesswork. But last month on a dig near Bath, the GPR guy found this straight line running through the field. The trench guys had already dug 3 pits in that area and found nothing. He pointed at his screen and said "it's 4 feet down, between your second and third pit." Sure enough, we dug a test slot right there and hit a compacted gravel layer. Turned out to be a Roman road nobody knew about. Has anyone else had a method they dismissed that later proved them wrong?

2 comments

2 Comments

abby_robinson5818d ago

Oh wow, seriously?! Wait, so you mean the guy literally calculated the depth and location just from those blurry blobs on a screen? That's insane. I always figured it was more like a divining rod situation, like you wave it around and hope for the best. But the fact that he could pinpoint it between the pits you already dug is wild. That turns it from a gadget into a genuine tool in the right hands. Makes me wonder how many other things we've walked right over because the person operating it was just winging it.

sanchez.mary24d ago

Between your second and third pit" - that part got me. Not to be that person, but GPR doesnt actually show you a perfect picture of what's underground like you see on TV. It gives you these blurry radar reflections that someone has to interpret. The real trick is the operator knowing what they're looking at. I've seen guys completely miss obvious walls because they didnt understand the software. So it's not really the method that was wrong before, it was probably just bad operators. Glad you had a good one on that Roman road though, that's a solid find.