3D Laser Scanning Historical Caves

3D Laser Scanning Historical Caves

LiDAR News had the opportunity in December 2021 to interview David Bodo on his firm’s investment in and use of 3D laser scanning on some challenging project environments. 

Can you please provide a brief overview of your professional background and experience with 3D laser scanning/LiDAR technology, as well as a brief history of the growth of your group and its use of 3D technology? Please include an idea of the timelines.

David Bodo & Associates (Bodo Surveying) was started by my dad, Dave Sr. in the late 1970’s as he saw a need for surveying in the energy industry. From early on, Bodo Surveying invested in new technology. 

Starting as just a two person company, we have grown to a 14 person team always looking for ways to improve our services and better serve our clients. Before purchasing our RIEGL VZ-400i in 2016, three members of our team attended TUC2016, a training seminar for Certainty 3D’s TopoDOT software. We were working on inner city improvement projects where our survey crews were collecting upward of 20,000 points per job. These points needed to be coded so that they could be drafted correctly. We realized that even with a 0.5% error in recording data, we could have 100 incorrect points. Even though projects were being videoed, correcting any mistakes was very difficult. The ability to provide our draftsman a 3D point cloud would help us provide a much more complete and accurate project without the need to revisit the project to update incorrect data.

Can you provide an inventory of some of the primary 3D surveying and mapping hardware and software that you currently use, as well as any other related products? Please include an idea of the timeline of purchases. 

Along with the purchase of our RIEGL VZ-400i in 2016, we also invested in Certainty3D’s TopoLIft. The lift allows us to mount the VZ-400i in the bed of a pickup truck and remotely control both the lift and the RIEGL from the safety of the cab of our truck. 

With the aid of the lift, the scanner is higher above the ground, allowing us to move further between scans. We are able to scan close to 9000’ in about 2 hours. 

Registering the data in RiScan Pro, the data is filtered, combined, and colorized automatically, and then exported to TopoDOT. TopoDOT aids in extracting the needed data and the ability to overlay the point cloud with the high resolution photos the RIEGL took during scanning. We are now using programs like CloudCompare and Meshmixer to create stunning visual 3D models of our data that can be shared and even modeled using a 3D printer.

What attracted you to the use of RIEGL hardware and software? Did you look at other products? Why did you choose RIEGL?

When looking into LiDAR for use on our projects, we had shied away because of the additional time it took with multiple targets needed for each scan position. Many of our projects were lineal and cover around 5000’. We felt that it wasn’t a good fit for us. When attending TUC2016, Ted Knaak from Certainty3D recommended I talk with Tan Nguyen from RIEGL about the VZ-400i. Going into the meeting, I knew that I wouldn’t be buying a scanner, but after seeing the speed of collection, the need for minimal targets, and the ease of registration, the plans were in motion to purchase a VZ-400i before we left Orlando.

How do you integrate RIEGL products into your workflows? What were some of the challenges with that? What were some of the best practices and lessons learned?

The RIEGL has given us many different opportunities to improve our work, increase safety, and the ability to create a dramatic snapshot of existing conditions. The snapshot has proven to be a value that was hard to foresee. 

We had a basic project of surveying a road crossing that we chose to use the VZ-400i on. The project was completed, and a couple years later, a lawsuit was presented that the construction project allegedly changed the grades around an adjoiner’s home. Using the immense amount of data showing the existing conditions outside of our original scope of work, we had enough data to compare our original data to current captured data. This proved that there was no noticeable change in grades, saving our client the expense of the lawsuit.

Can you provide a brief overview of two or three of the projects where you made use of RIEGL’s technology? Can you provide any thoughts on time savings vs. other methods? Any thoughts on return on investment?

In late 2019, I received a message from Dr. Bryon Schoeder, soon to be Director for the Center for Big Bend Studies at Sul Ross State University in Alpine, Texas. He had a cave system that has historical benefits as far back as 30,000 years ago. 

Originally, it was a birthing area for the North American Sloth. Later, it became a significant habitat for the Hunter – Gatherers of the areas and a burial site going back more than 2,000 years. This site had been severely looted and Bryon wanted to capture as much data of the current conditions as possible. 

In early 2021, I was finally able to travel to the cave system and aid Bryon in mapping the cave. Immediately, the difficulty in capturing this site was apparent, with narrow shafts that, at times, were less than a meter tall. The RIEGL mounted on a carbon fiber NEDO tripod was able to navigate the difficult terrain. We were able to create a 3D model of the entire site. 

Mapping this site with traditional means would have been extremely difficult due to the passages, but with the ability to create a 3D model, we are able to extract what is needed to accurately map the features.

What do you see in the future for the use of 3D technology on your projects? Are you investigating other advanced technologies that will open up new business opportunities?

As we scanned the cave system, even with the versatility of the VZ-400i, we found some areas that we couldn’t navigate safely with the scanner. Using a program called MetaShape, Bryon was able to take a plethora of photos and create an .las 3D model that we were able to combine with our data to complete our 3D model. 

Being able to use multiple and extremely different technologies to complete our projects is essential when working in difficult environments. Since our initial survey in spring, we have since returned to the area and manned with a handheld scanner, we were able to add even more data to our dataset. 

Each of the three technologies we used have their own unique advantages, but being able to use the three together is truly proof that understanding the limits of ourselves and our equipment is going to help move our company at the fast changing pace of our age.

Note – If you liked this post click here to stay informed of all of the 3D laser scanning, geomatics, UAS, autonomous vehicle, Lidar News and more. If you have an informative 3D video that you would like us to promote, please forward to editor@lidarnews.com and if you would like to join the Younger Geospatial Professional movement click here.