The use of drones in surveying, 3D modeling and geomatics is profoundly transforming data collection methods. Thanks to their on-board sensors (LiDAR, high-resolution RGB cameras, RTK systems, advanced software) drones can now document vast territories with previously unattainable speed, precision and efficiency.
In this case study, DroneXperts collaborated with Topo 3D to evaluate the technological evolution between a survey carried out in 2012 and a new acquisition in 2025 at Parc Frédéric-Back, a site in Montreal formerly known as the Miron quarry.
Context and purpose of the case study
The aim of this case study was to produce a point cloud and an orthomosaic of Frédéric-Back Park, an area measuring approximately 1 km by 2 km, and then to compare these new results with a deliverable produced in 2012. The aim of this approach was not only to highlight the evolution of surveying technologies over the years, but also to show the extent to which modern methods now make it possible to reduce time, cut costs and improve the quality of the data obtained. It also highlighted the added value of LiDAR and RGB sensors mounted on UAVs, whose accuracy and efficiency far surpass the tools of yesteryear. By directly comparing the two approaches, Topo 3D wanted to measure in tangible terms the real contribution of drones to the surveying of a large-scale site.
Introducing Topo 3D
For over ten years, Topo 3D has established itself as a major player in the Quebec surveying industry, renowned for its expertise in 3D surveys and digital terrain modeling. The company carries out more than 300 projects every year, ranging from small technical sites to large-scale mandates involving several intervention zones. Its team, made up of specialists in surveying, 3D modeling, BIM and LiDAR acquisition, both terrestrial and aerial, operates both in Quebec and internationally, notably in the mining, municipal and industrial sectors. We also work with major organizations such as Hydro-Québec, assisting them with their surveys, inspections and technical analyses.
The case study
DroneXperts intervention
DroneXperts carried out a complete LiDAR and RGB acquisition of the site, using the very latest technology. For this mission, the team deployed a DJI Matrice 400 equipped with the DJI Zenmuse L2 sensor, a combination renowned for its reliability and data quality. The flight was carried out in RTK mode, thanks to the installation of a D-RTK 3 base directly on site, guaranteeing centimetric accuracy throughout the acquisition. Four additional control points were used to validate the results and ensure overall model consistency.
The operation was carried out at an altitude of 120 m in AGL mode, with terrain tracking based on a digital terrain model, to optimize the regularity of the capture. The drone flew at a speed of 5 m/s, while the LiDAR sensor operated in non-repetitive scan mode with RGB colorization enabled. Five returns were configured to maximize vegetation penetration and achieve a more homogeneous point density, resulting in an expected point density of around 500 pts/m². The flight plan called for 50% lateral LiDAR overlap and 80% frontal RGB image overlap, guaranteeing sufficient coverage to generate a continuous point cloud and a highly accurate orthomosaic. During this first mission, around half of the total terrain was captured.
Once the data had been collected, pre-processing of the LiDAR point cloud validated the control points and confirmed the quality of the geo-reference. The data were then integrated into DJI Terra, with processing in the NAD83 MTM zone 8 coordinate system for the horizontal and CGVD28 HT2 for the vertical. The “Precision Optimization” and “Smoothing” options were activated to improve point consistency prior to full model reconstruction. The point cloud was generated in 100% “Density” mode, followed by 2D reconstruction to produce a high-resolution orthomosaic, perfectly aligned with the LiDAR data.
This rigorous workflow ensured detailed and homogeneous acquisition, while allowing control of point density, geometric accuracy and the quality of the associated images. All in all, it confirms the ability of modern drones to deliver, in a short space of time, complex data previously impossible to obtain so efficiently.
Comparison of results: 2012 vs. 2025
Analysis of the two surveys highlights the major gap between modern technologies and traditional methods. The 2025 survey, carried out with a drone equipped with a new-generation LiDAR, produced denser, more complete data in a significantly shorter time. Conversely, the 2012 campaign, carried out with C10 ground scanners, required heavy logistics, several days of field work and a more limited quality of deliverables, particularly in vegetated areas.
| Compared element | Results 2025 (Drone + modern LiDAR) | Results 2012 (Scan terrestre C10) |
|---|---|---|
| Acquisition period | 52-minute flight | Around 10 days of field surveys, up to 6 people mobilized |
| Treatment time nt | 2 h (1h30 point cloud + 30 min orthomosaic) | Approx. 20 days including processing and compilation |
| Technology used | Drone + LiDAR Zenmuse L2 with real-time feedback | 2 C10 terrestrial scanners, a hundred stations |
| Deliverable quality | Dense cloud, color, no holes | AutoCAD file without color, some areas without points |
| Detail and legibility | Highly detailed structures and reliefs | Lower resolution, less geometric precision |
| Plant penetration | Excellent thanks to multi-turn LiDAR | Weak, difficult to capture under plant cover |
| Feedback during acquisition | Yes, real-time validation | No feedback before post-processing |
| Additional field trips | Unnecessary thanks to live control | Frequently used to fill gaps or double-check zones |
| Overall efficiency | Precise, complete, fast and cost-effective delivery | Time-consuming, costly and logistically intensive process |
Which drone and which sensors were used?
DJI Matrice 400
Designed for demanding professional missions, DJI’s Matrice 400 stands out for its robustness, stability and ability to integrate the most advanced sensors. It has become a must-have for surveying, inspection and 3D modeling operations requiring impeccable precision and efficiency over vast territories.
Main features :
- Centimeter accuracy thanks to RTK system
- Long autonomy for large-scale projects
- Full compatibility with professional LiDAR sensors
- Excellent performance in tough conditions
- Reliable, stable platform for complex missions
DJI Zenmuse L2
Zenmuse L2 is a new-generation LiDAR sensor, renowned for its ability to produce dense, accurate and perfectly colored data. Designed to offer an exceptional level of detail, it efficiently captures complex environments, including under vegetation cover, while ensuring seamless integration with DJI’s software ecosystem.
Main features :
- High point density for highly detailed readings
- Improved plant penetration thanks to multiple returns
- Precise fusion of LiDAR and RGB data
- Fast, efficient processing in DJI Terra
- Uniform, high-precision results on large surfaces
A combination tailored to project requirements
The combination of the Matrice 400 and the Zenmuse L2 is now the benchmark solution for medium and large-scale surveying projects. This configuration enables rapid coverage of vast areas while generating remarkably dense data, with centimetric accuracy that meets the highest professional standards. The consistent quality of deliverables, combined with a considerably more efficient acquisition and processing process, significantly reduces operating costs.
Environmental impact and continuity of operations
The use of drones for a project of this scale contributes directly to reducing the environmental footprint of data collection. By limiting human movements and the presence of heavy machinery on site, operations become not only safer, but also much less intrusive for natural environments and adjacent activities. Aerial data collection also enables us to work more quickly, without disturbing users, infrastructures or surrounding habitats.
DroneXperts, who are we?
For over ten years, DroneXperts has been supporting organizations wishing to integrate drones at the heart of their operations, whether for data capture, inspection, modeling or optimization of their field processes. We have developed a comprehensive approach based on three pillars: technical expertise, professional training and operational support.
As a center of expertise dedicated to drone technologies and specialized sensors, DroneXperts provides companies with :
- technical advisors capable of identifying the best solutions for specific field requirements;
- a vast inventory of UAVs, sensors, LiDARs and payloads to suit every level of requirement;
- experts in photogrammetry, LiDAR, inspection and 3D modelling;
- field support and operational assistance services to secure every mission;
- comprehensive support from equipment selection through to implementation in internal processes.
We believe that integrating a drone is more than just buying a platform. It’s a real technological change that requires :
- people skills ;
- mastery of tools ;
- efficient processes ;
- and ongoing support to ensure optimum return on investment.
That’s why DroneXperts offers a range of structured solutions:
Professional training
Our certified training center supports teams at all levels to develop the skills they need to steal, capture, process and analyze their data independently. Our training courses cover :
- steering fundamentals ;
- advanced operations ;
- photogrammetry ;
- the use of specialized sensors such as LiDAR.
Operational support
We support companies directly in the field: implementation of best practices, optimization of flight plans, technical assistance during the first missions, calibrations, choice of sensors, analysis of renderings…
The aim: to secure drone integration and guarantee reliable results from the very first operations.
Strategic consulting and technology integration
Every project has its own particularities. Our experts analyze operational needs, budget, field context and precision requirements to recommend the most suitable platform: photogrammetric drone, LiDAR drone, thermal or multispectral payload, etc.
We also help our customers structure their internal procedures so that the drone becomes a stable, high-performance and durable tool.
Take your operations into the future with drone technology
The last ten years have seen a meteoric evolution in the technologies applied to surveying, 3D scanning and geomatics. UAVs, next-generation LiDARs, cloud software and modeling platforms are now essential tools for producing data that is more reliable, more complete and faster than ever before.
With the continuous improvement of sensors, automated data integration and the rise of intelligent systems, organizations can now :
- reduce their operating costs,
- save considerable time,
- improve the quality of their analyses,
- make better decisions based on rich, accurate data.
The future of land surveying and modeling is already changing, and the drone is now an essential tool.