The Alpha Survey faced significant challenges in conducting topographic surveys along a rugged and forested 6.6 km coastal road in South Korea. Traditional methods proved time-consuming and inefficient, while the terrain posed safety risks. By leveraging DJI Zenmuse L2 LiDAR technology and DJI Terra software, Alpha Survey overcame these obstacles. The comprehensive solution enabled efficient, precise data collection, leading to enhanced road safety, reduced travel time, and a boost in local economic recovery.
About Alpha Survey
Alpha Survey is a leading surveying service provider in South Korea, known for its expertise in road, railway, airport, and water supply system projects. Widely recognized for its high-precision solutions, the company operates across South Korea and Southeast Asia in countries like the Philippines and Cambodia. For the linear improvement project on National Route 77, spanning from Jangjwa to Yangchon, the goal was to straighten a winding coastal road essential for accommodating around 7 million tourists annually. Due to the challenging terrain and dense vegetation, innovative surveying techniques were necessary. Alpha Survey, the service provider, played a crucial role in overcoming these complexities.
Surveying Challenges: Navigating Rough Terrain for Accurate Data
Surveying the 6.6 km coastal road presented several obstacles for Alpha Survey, including rugged mountainous terrain, dense forestry, and challenging elevation changes. Traditional manual surveying methods required excessive resources, including larger teams and extended timelines, creating risks to personnel safety. Furthermore, photogrammetry alone was insufficient in providing precise ground measurement data under dense vegetation due to weather limitations and visibility constraints, leaving the team unable to generate accurate Digital Elevation Models (DEM) critical for engineering projects.
The winding route, marked by steep curves, also contributed to high traffic accident rates and congestion—highlighting the urgency for accurate topographic data that could address these inefficiencies while enabling safer and faster project execution.
Innovative Approach: Revolutionizing Surveying Techniques
Deploying DJI Zenmuse L2 and LiDAR Technology
To tackle the challenging terrain, Alpha Survey adopted advanced technologies, including DJI Zenmuse L2 LiDAR system mounted on the Matrice 350 RTK drone. The Zenmuse L2’s high penetration capability and multi-return technology made it ideal for collecting accurate ground points, even under heavy tree canopies. Compared to its predecessor, the Zenmuse L1, the Zenmuse L2 offers improved flight elevation capabilities, enhancing the flight safety. Additionally, the L2 provides enhanced data precision in forested areas, thanks to a new IMU module, smaller laser spots, and denser point clouds, which enable better penetration through dense vegetation.
Streamlined Data Processing with DJI Terra
For data processing, Alpha Survey used DJI Terra. This lightweight yet powerful software allowed on-site point-cloud processing using laptops, enabling immediate assessment of collected data. The free lifetime post-processing feature of DJI Terra further simplified workflows, delivering outputs like contour lines, DEMs, and DSMs in the international LAS format for seamless engineering integration.
Workflow Overview
- Equipment Preparation: Through field readiness assessments, Alpha Survey deployed LTE-enabled drones, extra batteries, and real-time monitoring tools.
- Flight Plans and Real-Time Terrain Tracking: Using DJI Pilot 2 software, precise flight paths and DSM data were created on-site for accurate pilots and terrain analysis.
- Data Acquisition and Validation: The LiDAR system captured real-time point-cloud data, ensuring immediate quality control during operations. On-field verification of critical terrain data further validated survey accuracy.
By integrating these technologies, Alpha Survey achieved a robust solution that transformed complex on-ground triangulation methods into a more streamlined, safer, and faster survey process.
"With traditional methods, surveying mountainous terrain this detailed would have been impossible within our timeline. DJI Zenmuse L2 and Terra elevated our capabilities, not just in data quality but also efficiency and safety."
Lee Jung-Min, Team Leader, Alpha Survey
Groundbreaking Results: Efficiency and Precision Unleashed
Efficiency and Cost Savings
Alpha Survey accomplished its goal of surveying the 6 km coastal route, including three tunnel sections, in only five days. Compared to traditional methods requiring a team of three people or more over extended timelines, this drone-based LiDAR approach allowed for a two-person team to complete the project efficiently. Surveys that would have previously taken weeks were executed at a fraction of the time, demonstrating a 3–4x improvement in resource efficiency.
For areas with dense forestry and steep elevation changes, the Zenmuse L2’s precise data penetration technology extracted ground points easily, ensuring that no segment of the route went unaccounted for.
Improved Accuracy and Quality
The project delivered a high-quality 1:1000 scale topographic map, capturing fine details necessary for road construction and engineering requirements. By augmenting LiDAR data with ground control points (GCP), Alpha Survey achieved unparalleled data integrity, enabling confident decision-making for construction and safety improvements.
Enhanced Safety
Switching to drone-based surveying eliminated the need for personnel to traverse hazardous terrain. The automated workflows of the drones significantly minimized safety risks while sustaining high-quality data acquisition standards.
Economic and Social Impact
The road improvement project will reduce congestion, cut travel times, and enhance passenger safety. These advancements are anticipated to promote local economic recovery by increasing accessibility and attracting greater tourist demand. These tangible societal benefits underscore the critical role Alpha and DJI technologies played in delivering impactful results.
Key Metrics at a Glance
- Survey Length: 6.6 km, including tunnel sections
- Survey Time: Completed in 5 days vs weeks manually
- Effort Saved: Reduced team size from 3+ to 2 personnel via drones
- Scale of Deliverables: 1:1000 topographic map
Visionary Impact: Transforming the Future of Infrastructure
Alpha Survey’s strategic adoption of DJI Zenmuse L2 and Terra software revolutionized the National Route linear improvement project. By innovating beyond conventional approaches, the team delivered efficiencies, precise topographic data, and significant safety improvements. This successful deployment highlights the potential of drone-based LiDAR solutions for transforming infrastructure projects globally.
Moving forward, Alpha Survey plans to adopt similar advanced workflows in future projects across South Korea and Southeast Asia. If your organization faces similar challenges in delivering accurate data on tight timelines, DJI Enterprise solutions might be the partner you need.
