DIY LiDAR Thread

[rjack321]

What you desire already exists (at least for dry caves due to the limitations of water and lasers) assuming you are willing to use actual "conventional" survey stations.
Home
Perhaps take one of those and retrofit a laser with more power and/or a less scattering wavelength suitable for UW measuring as a start.

Assuming you want to ditch conventional survey station usage and go with a completely mobile device/strategy... Bill Stone already did what you are proposing positionally on a scooter minus the laser parts 3 decades ago.

http://www.advanceddivermagazine.com/ezinefreearticles/3DSonarMapper.pdf

His current technology is completely autonomous and doesn't require a diver or a scooter at all

I have to ask @Addison Snyder... Have you ever surveyed a cave at all?

 

[Addison Snyder]

doesn't have the horsepower for online streaming at 1080p

Encoding/compressing video is vastly different from doing some basic trigonometry and IO. Technically speaking, the pi doesn't even have to calculate this stuff, just log it (even though it's probably got many magnitudes the compute power to do it ~100 times a second).

All cool stuff. I wish you luck on your pursuit.

Thanks dude, I hope something comes of it!

What you desire already exists (at least for dry caves due to the limitations of water and lasers) assuming you are willing to use actual "conventional" survey stations.
Home
Perhaps take one of those and retrofit a laser with more power and/or a less scattering wavelength suitable for UW measuring as a start.

That's SO COOL, and pretty much exactly what I had planned! Glad someone's done it for dry caves! Even cooler that it's all open source, reproducible, etc. I'm definitely going to try out the IMU used in that for my dirt-cheap prototype. Curious how bad/good a $100 IMU is for this.

Assuming you want to ditch conventional survey station usage and go with a completely mobile device/strategy... Bill Stone already did what you are proposing positionally on a scooter minus the laser parts 3 decades ago.
http://www.advanceddivermagazine.com/ezinefreearticles/3DSonarMapper.pdf His current technology is completely autonomous and doesn't require a diver or a scooter at all

Also insane. I've heard about this project, and how they pushed through this massive satellite-like DPV with a dozen or so sonar rangefinders. Pretty wicked, considering what they had in 1990.

I have to ask @Addison Snyder... Have you ever surveyed a cave at all?

No! I'm gonna get trained on that eventually! I promise!

In all seriousness, I am definitely putting the cart before the horse on this one, assuming conventional cave diving survey standards. But I'm hoping to maybe change that for the better (by piggybacking off of technological advances and smashing them together). In the same way that we don't use divetables and have a bit more YOLO attitude with deco/computers, maaayybe 5-25 years from now people will look back at certain passageways (ya'know, the bigger DPV-able ones) and consider you crazy if you surveyed it 'manually' and stuck with 2D illustrations. Or maybe I'm wrong. I dunno. I look at videos of pipeline contractors using bajillion dollar top-of-the-line equipment to do this today (or ~10 years ago) using these principles, and wonder if we as a cave diving community could pull it off (albeit not sub-millimeter accuracy) for ~4-5 figures.

Spoiler

Maybe I'm a dreamer, but I'm not the only one

 

[Addison Snyder]

A little update on this whole thing:

SLAM and LiDAR Cave Mapping

I've been holding off on this post for a couple of months now, but I've been working on mapping caves using visual-inertial SLAM. There's still a ton of work to do, but I'm getting there with the process and it's only getting better over time. I could practically write a thesis on it all, but to...

scubaboard.com