Dropped $400 on a ground-penetrating radar rental and found nothing but old water pipes

I argued with my professor that GPR was worth it for our survey vs traditional test pits, but after two days of scanning a field in Vermont, we only got false positives from 1920s plumbing - has anyone else had a geophysics tool completely fail to deliver?

2 comments

2 Comments

black.amy1mo ago

Third time using GPR on a site near Burlington and the thing just kept finding old drain lines from the 1800s. We finally gave up and dug a test pit by hand. Found a whole 6 feet of clean soil before we hit anything interesting. I feel your pain on the 400 bucks, that's a lot of money for basically a fancy pipe finder. Professors mean well but they don't always get that real world dirt is full of random junk from the past.

emerycarr1mo ago

Have you tried adjusting the gain settings as you go? I've had GPRs get confused by old clay drain tiles more times than I can count, they just keep ringing off that curved surface. A lot of folks don't realize you gotta dial it back once you start seeing those repeating hyperbolas or you'll waste hours chasing ghosts. Next time try running a line perpendicular to the drains first to map the pattern, then you can avoid them or account for them better. That hand dug pit sounds like a smart move honestly, sometimes the old ways just work.