Video - LIDAR survey of Cwmystwyth Lefel Fawr

[royfellows]

This is a video by Ian Cooper of Shropshire caving and Mining Club of a LIDAR survey using home made equipment. Its truly an amazing piece of work.

https://www.youtube.com/watch?v=jVhROpHQ8eY

 

[Mr Mike]

Yes, very impressive Roy. Do you have details of what he used, did he build it from scratch of was it one of the open source scanners / survey devices - irrespective of which a mean feat !

 

[royfellows]

The link was sent to me earlier in an email, the first I knew about it. Hopefully, someone may come along who knows more.

 

[Mr Mike]

I wonder if its the Caveatron: http://caveatron.com/  ??

 

[sinker]

Not often that I'm speechless...but...WOW! 

 

[T pot 2]

A stunning piece of work.
Fantastic medium which probably took many hours to prepare before publishing,
thank you for sharing this.
T pot

 

[ChrisJC]

The mind boggles at the maths involved.

Chris.

 

[tomferry]

Am most impressed that has taken some serious work I imagine,  brilliant quality it reminds me of the other topic on uk caving last week lost gold in ww2 that shows you very similar footage of inside the mountains where the tunnels are ,  i am guessing he owns the tools and access to the software to create this ?  Or is this on the most recent I phone and he has done thousands of scans and jig sawd them together and created a brilliant video?

 

[ttxela2]

Amazing stuff, how long did it take to produce?

 

[Rob]

I wonder if its the Caveatron: http://caveatron.com/  ??

I'd heard of this device but never seen any details of it or the open source project. Looks very interesting, would love to hear more about it. 

 

[RobinGriffiths]

Blimey. Like the mine truck scene in Temple of Doom, only better.

 

[royfellows]

I am going to try and get someone on the forum from SCMC, there are a lot of questions in the air which I cannot answer.

 

[Cantclimbtom]

I'm just gob-smacked!  That's truly astonishing.

How many hours/months/years work must that have taken??

 

[royfellows]

I know little about LIDAR but to my eyes that video captures the very soul of the mine.

 

[Mr Mike]

Very simply, a laser scans the passage, slice at a time. The time it takes for the laser light to hit a bit of surface is measured, so you get the distance relative to the source (the instrument). This is done 1000's of times on a 360deg rotation. Then you move along a bit, repeat - this starts generating the point cloud, that is then processed in to the fancy graphics.

 

[Ian Adams]

Absolutely fantastic 

 

[aricooperdavis]

I'm interested in the fancy graphics! How does the rendering make the bright bits? Is it just the point density in the point cloud? Could the points be stiched together into surfaces (non-manually, presumably!)?

 

[Grout1]

I am going to try and get someone on the forum from SCMC, there are a lot of questions in the air which I cannot answer.

Ian Cooper is the main instigator of this project, along with Pete Eggleston and Kelvin Lake - all from Shropshire Caving & Mining Club

Ian is quite happy to provide information and explanations - he just has to work out how to re-register himself back onto UK Caving.
Tricky stuff.

Hopefully you will all be enlightened on the methodology in the near future.

Ironically, Shropshire Mines Trust have been involved with Network Rail's Prometheus project at Snailbeach, where professional LIDAR surveys are being compared with survey data acquired from autonomous drones.

Watch this space - remote mining of the Moon from the comfort of the hot tub is coming next

 

[Mr Mike]

I'm interested in the fancy graphics! How does the rendering make the bright bits? Is it just the point density in the point cloud? Could the points be stiched together into surfaces (non-manually, presumably!)?

It is the point density. Closer you are to an object the closer the points, further away they spread out more due to angles etc...

 

[Rob]

Interesting to see the two different datasets in that video, which suggests there are two different collection types are work.

The yellow (which looks to be a slightly lower data density) is very continuous and used in many of the connecting passages. The white/lighter data is mostly used in the chambers and has clearly visible circles on the floor, presumably below a fixed tripod location.

This mix looks very comparable with the Caveatron system which allows for either a walking passage collection type or a fixed chamber collection type. Either way, i'm very interested to learn more.

...Could the points be stiched together into surfaces (non-manually, presumably!)?

This would be awesome if possible, although my understanding is that most software that do this are not good when applied to cave data. Hopefully that is wrong, or will change soon...