8+ Years of Leveraging Aerial LiDAR in the Land Survey and Civil Engineering Industry

8+ Years of Leveraging Aerial LiDAR in the Land Survey and Civil Engineering Industry

Gene Roe, Founder of Lidar News speaks with Jeff Rizza, Remote Sensing Program Manager at DJ&A about the challenges of developing a new surveying business from scratch with integrity and cutting edge technology. 

Can you please provide a brief overview of your professional background (s) and experience, particularly with 3D laser scanning/drone lidar technology, and/or a brief history of the growth of the company and its use of 3D technology? Please include an idea of the timelines.

Throughout our 50+ year history, DJ&A has consistently adopted new technologies to improve the quality and efficiency of our civil engineering and land survey projects for our federal, state, and private clients. GPS survey equipment became part of our toolbox in the 1990’s and we swiftly adopted terrestrial laser scanning technology in the early 2000’s for infrastructure inspections and mapping. We were also one of the first civil engineering and survey companies to begin using UAS LiDAR in the mid 2010’s.

Over nearly a decade, we have used UAS LiDAR to collect topographic data on dozens of road corridor and site mapping projects, perform critical infrastructure inspections on structures such dams, bridges, and communications towers, and contributed to scientific research, such as NASA’s SnowEx program. Our LiDAR program is driven by rigorous land survey and engineering principles, ensuring our products are always delivered with accuracy and quality.

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

We use a large array of softwares to complete our 3D data processing and production of the associated deliverables. Trimble Business Center is used to process GPS and total station data, which is used to control and truth all our aerial and terrestrial mapping data. TBC is also used to process our terrestrial laser scans. Our LiDAR software suite consists of NovAtel Inertial Explorer, Phoenix LiDAR Systems SpatialExplorer, the TerraSolid suite, GlobalMapper, and ESRI ArcGIS Pro. We also often use CloudCompare for point cloud visualization and quality analysis. Custom python scripts are used for tiling, certain geospatial reprojections, and other bespoke applications. Imagery is typically processed in Pix4D, though we have also used Trimble Inpho, Agisoft Metashape, and SimActive Correlator3D. For 3D mesh reconstructions, we use RealityCapture and/or Bentley ContextCapture. AutoCAD Civil3D and various Bentely softwares, including MicroStation and OpenRoads, are used for mapping and drafting.

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

Phoenix shares our commitment to quality by using the best sensors and other hardware available on the market. We also feel Phoenix provides the best software for LiDAR processing in the SpatialExplorer product. As we also now fly LiDAR missions in manned aircraft and use Phoenix’s Mission Guidance software, which has been a great experience. Phoenix has also shown their commitment to being more than just a hardware provider by partnering with us multiple times over the 8+ years since our first purchase. Running into unexpected technical challenges is always a factor with advanced technologies and Phoenix has always been available and willing to help us work through those issues and has even gone above and beyond at times to ensure we can complete time-sensitive missions. We have also collaborated with Phoenix on multiple occasions to complete unique projects that require specific equipment, such as our work on NASA SnowEx.

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

We use a Phoenix LiDAR Ranger system to collect LiDAR with UAVs, manned aircraft, and in a mobile mapping configuration on a ground vehicle. Our projects consist largely of topographic surveys for civil engineering design of roadway corridors and site development, expansion, or redevelopment. A challenge we experienced early on was trying to use the mobile mapping configuration on projects that required ditches and downslopes to be captures. The shallow angle of the laser when mounted on a terrestrial vehicle makes it impossible to capture these features in some scenarios. When these features are needed, we now always plan to fly LiDAR.

We also use Phoenix’s Mission Guidance add-on module to the SpatialExplorer software for our manned LiDAR missions. This has been an excellent solution for providing flightline guidance and telemetry to the pilot and technician to ensure proper coverage and point density is captured.

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

We have used our Phoenix LiDAR Ranger system on dozens of projects for topographic mapping of sites and roadway corridors. For any site larger than approximately 20-30 acres, or a corridor 5 miles or longer, we find UAV LiDAR to be a very efficient and accurate tool. The largest sites we have flown with a UAV approach 2000 acres or 30 miles in length. At this upper boundary, depending on the terrain and point density requirements, it begins to become more cost effective to use a manned aircraft, which is why we have developed a relationship with a partner to fly our LiDAR system on a Cessna 172.

A unique project for us involved collecting LiDAR on snow surfaces for the NASA SnowEx project. We rented a RIEGL MiniVUX-based system from Phoenix for this particular project because the MiniVUX uses a different wavelength infrared laser that reflects off snow with more efficacy than our VUX-1 sensor. To extract snow surfaces successfully and accurately, we had to develop custom surface point classification techniques, which required quite a bit of experimentation, but we were able to successfully create a snow surface classification technique with similar accuracy to that of conventional ground classification.

We have also completed dam inspections with UAV LiDAR. The SKQ hydroelectric dam near Polson, Montana has a concrete stair-step spillway used to dissipate the energy of falling water. These steps must be inspected periodically for degradation and structural integrity, which has traditionally been done by inspectors repelling down into the spillway basin, a time consuming, complex, and risky procedure. In 2022, DJ&A used our Phoenix LiDAR system to collect LiDAR and high resolution imagery of the spillway to reconstruct a 3D mesh used for virtual inspection and documentation. With this new process, we have established an easily repeatable workflow that allows consistent documentation and comparison of the structure over time.

What do you see in the future for the use of Phoenix Lidar’s 3D technology on your projects? Are you investigating other advanced technologies that will create new business opportunities?

Moving forward, we will continue to use our LiDAR system for topographic mapping projects similar to those described above. We will also continue to use the Missions Guidance software for our manned missions. With our acquisition of Woodland Solutions Group, who focuses on providing their customizable MobileMap GIS software and services, we aim to provide aerial LiDAR services for remote sensing applications for the Forest Service and other stakeholders in the forestry industry. We are also always looking to partner with new clients in the construction, energy, mining, earthwork, and other industries to provide aerial LiDAR and imagery services alongside our terrestrial laser scanning, conventional survey, engineering, and environmental services. 

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