What kind of signal strength range/penetration do you expect?
We could REALLY use one, at my farm.  The previous owner ran this, that, the other willy-nilly.  No ides where the underground plumbing and electrical wiring is, so every time we need to dig, it's random luck nobody dies.

LIDAR is surface scanning. It cannot penetrate opaque materials. It sounds like you need ground-penetrating RADAR.

Got it.  My misunderstanding was based off of Archaeologists using LIDAR to detect hidden ruins in rainforests.

Could it be used as a sort of artificial horizon for ultralight aircraft?  Light weight being a necessity and getting down safely in changing light conditions can often be tricky.