LiDAR Drone Mapping-Field Overview

This is a pre-flight field demonstration/overview of the Yellow Scan Mapper, a high-precision LiDAR system mounted on our DJI Matrice 210 drone. The equipment operates with its own power source and internal sensors, requiring specific aerial maneuvers like forward and backward shifts to trigger data collection. To ensure centimeter-level accuracy, we pair this operation with a base station to log satellite data, which will later be merged with the Mapper’s output files to refine the geographic positioning. While the payload includes an RGB camera for colorizing maps, the primary focus is generating dense topographic point clouds rather than traditional photography for generating orthomosaics. Flight altitude and speed must be carefully managed to maintain laser signal strength and avoid data gaps. Successful mapping relies on balancing the drone’s battery limitations with the need for overlapping passes to eliminate edge fuzziness. YellowScan is a French company founded by Dr. Tristan Allouis , who needed better tools for studying forests and set out to craft a system designed to be autonomous, easy to use, with rapid processing times. The version of their mapping tools that we have here is on the lower end of what they produce (read: cheapest!). But even this entry level sensor is fantastic. Our Mapper LiDAR sensor emits approximately 240,000 near-infrared (905 nm wavelength) laser shots per second using a non-repetitive scanning pattern across a ~70° field of view, with each pulse capable of producing multiple returns from vegetation and ground surfaces. This system of rapid laser pulse emissions and multiple-return detections across a wide scanning field of view allows us to construct. The bundled RGB camera adjacent to the LiDAR captures imagery used to colorize the final LiDAR point cloud. A unique aspect of YellowScan’s system operation is its physical trigger; rather than using a software command, the operator must trigger the internal IMU to toggle on/off our LiDAR data collection. We do this by flying the drone in a rapid forward, backward, and curved motion to start and stop data collection once we are at the approximate altitude to map. The system is designed for a fast, “turnkey” workflow, making it suitable for high-demand applications like impact assessment, construction, and mining where users need precise results without extensive manual finessing or post-processing back at the lab. To achieve centimeter-scale accuracy, the internal LiDAR data is processed alongside precise location logs collected by a Trimble satellite receiver base station. While awesome, our current set-up does have several operational constraints as configured here (due to using our old DJI Matrice 210). Chief among these is our limited flight time of roughly 15 minutes due to the heavy payload and a recommended altitude limit of 70 meters to maintain data strength. Exceeding this altitude or flying too fast can result in “fuzzy” data at the edges of the scan or a sparse zigzag pattern on the ground, which reduces the quality of the topographic reconstruction. That said we are able to fly at roughly 20 mph and can cover a good amount of ground even with only a 15 minute flight time. To see the initial output after a quick flight, check here: https://youtu.be/o5LmAJSsrPs