How Diodrone overcame geotechnical engineering challenges in Australia for a 170km long rural road monitoring
The differentiator for Diodrone is the high quality of the data they can collect thanks to YellowScan solutions.
What is the challenge?
Diodrone’s client is responsible for managing geotechnical risks along a 170km long rural road which travels through remote and rugged terrain in Australia that is prone to landslides. Diodrone conducts routine inspection and geotechnical risk assessments as part of their geotechnical management plan for their client. However, the rugged nature of the area, dense vegetation and large sandstone escarpments limits the ability of conventional inspections to assess only the slope areas which are immediately adjacent to the roadway, leaving the majority of the slope largely unassessed and the risk profile uncertain.
YellowScan Surveyor was utilized to survey the slopes on both sides of the valley from creek to crest, covering an area of 400ha of mountainous terrain, exceeding 250m of vertical relief in some areas, in 4 days. “Flying low and slow with the Surveyor and processing with high scan angles achieved more than 400 points / m2 – providing incredible detail of surface topography including cliff faces, inside caves and beneath overhangs” commented Zack Wasson, CEO and Founder of Diodrone. “We purchased our first LiDAR unit from YellowScan about 4 years ago when they were one of the first companies to provide a quality LiDAR offering in the market. YellowScan’s equipment has a high level of accuracy which is what we require to deliver high precision data outputs for our client. Their customer support also gave us an advantage and we consider them a partner, not just a vendor.”
For this project, it took Diodrone 4 days operating along 5km of road length and capturing an 800m corridor width with up to 250m of vertical relief. Pre-programmed flights were optimized to increase point density and data capture along cliff faces and within caves.
Some of the details from the project
- Number of flights: 27
- Survey size: 400 ha
- Flight speed: 4 m/s
- Flight altitude: 50 m AGL
- High density data
- Detailed DTM beneath dense vegetation
- 50mm RMSE
- Variable scan angle to optimize point density in caves and steep terrain
The data from the YellowScan Surveyor produced a high-resolution LiDAR point cloud was then classified for ground points with extensive manual refinement by Diodrone to ensure that boulders, erosion gullies and other geological features were retained in the ground classification and evident in the resulting digital terrain model (DTM). The resulting deliverables provided geotechnical engineers with a high-fidelity DTM for use in rockfall modelling as well as identifying the location and extent of boulders, landslide debris, erosion gullies and overhanging rock formations – essentially providing a heatmap of potential rockfall sources throughout the assessment area. The data reduced uncertainty and gave the geotechnical engineering team from Diodrone’s client the confidence in the risk profile to enable informed and optimized decision making, ultimately leading to the success of the project.
NB: Author Geoffrey Riggs