The L1 sensor combines a sophisticated laser-scanning (LiDAR) system with a co-aligned high-quality photogrammetry camera in a fully integrated package for the DJI M300 RTK unmanned aircraft. The L1 sensor is a compact but powerful drone-based laser scanning system with an integrated RGB camera which can be used to colourise the LiDAR point cloud or as a standalone photogrammetry tool. The L1 is designed to be operated from the DJI M300 RTK unmanned aircraft, and is seamlessly integrated with that platform to provide an out-of-the box laser scanning solution. Specifications For the full specification see the manufacturer website: Zenmuse L1 - Specifications - DJI General: Weight 930±10 g IP Rating IP54 Supported Aircraft Matrice 300 RTK Operating Temperature Range -20° to 50° C (-4° to 122° F) 0° to 50° C (32° to 122° F) (when using RGB mapping camera) Storage Temperature Range -20° to 60° C (-4° to 140° F) LiDAR: Detection Range 450 m @ 80% reflectivity, 0 klx ; 190 m @ 10% reflectivity, 100 klx Point Rate Single return: max. 240,000 pts/s ; Multiple return: max. 480,000 pts/s Real-time Point Cloud Colouring Modes Reflectivity, Height, Distance, RGB System Accuracy(RMS 1σ) Horizontal: 10 cm @ 50 m; Vertical: 5 cm @ 50 m NOTE: these figures seem to have been derived empirically by DJI, but they do not explain exactly what they mean or the GNSS method used. We suspect they refer to positional accuracy of a point cloud relative to an absolute reference in the absence of any additional control measures, and probably using a network RTK solution which may have involved a long baseline. Maximum Returns Supported 3 Scan Modes Non-repetitive scanning pattern, Repetitive scanning pattern FOV Non-repetitive scanning pattern: 70.4° (horizontal) × 77.2° (vertical) ; Repetitive scanning pattern: 70.4° (horizontal) × 4.5° (vertical) Laser Safety Class 1 (IEC 60825-1:2014) (Eye Safety) RGB Camera: Sensor Size 1 inch Effective Pixels 20 MP Focal Length 8.8 mm / 24 mm (Equivalent) ISO Photo: 100 - 3200 (Auto), 100 - 12800 (Manual) Photo Format JPEG Video Format MOV, MP4 Storage: Raw Data Storage Photo/IMU/Point cloud data storage/GNSS/Calibration files Supported microSD Cards microSD: Sequential writing speed 50 MB/s or above and UHS-I Speed Grade 3 rating or above; Max capacity: 256 GB Recommended microSD Cards SanDisk Extreme 128GB UHS-I Speed Grade 3 SanDisk Extreme 64GB UHS-I Speed Grade 3 SanDisk Extreme 32GB UHS-I Speed Grade 3 SanDisk Extreme 16GB UHS-I Speed Grade 3 Lexar 1066x 128GB U3 Samsung EVO Plus 128GB Multiple Returns and Point Density The L1 is configurable to record 1, 2 or 3 returns per pulse, providing a very useful vegetation penetration capability that can provide information on both the canopy structure and the underlying topography. Scanning rate is also configurable. We can further control the point density of the resulting dataset by configuring the aircraft flight speed, flying height, the overlap between successive scans and repeated overflight with a grid pattern. The multi-rotor M300 drone platform provides huge flexibility in this respect, having essentially no lower limit to either flight speed or flying height, and very high point densities are possible. In initial flight tests we were able to achieve well over 2000 points per square metre while still covering multiple hectares in a single flight. The high band-width telemetry of the system allows us to view the evolving point cloud in real time as the aircraft flies. Scanning Modes Two main acquisition modes are provided - 'repetitive' mode, where the laser scans very rapidly across track as the aircraft flies along (i.e. a more conventional survey mode), and 'non-repetitive' mode, where the laser scans across all axes within the sensor housing, so that the aircraft can be held stationary while the sensor is directed at a target to build up a point cloud. By flying around the target in this mode a very comprehensive point cloud can be developed, even of structures of very sharp vertical relief (e.g. outcrop, isolated tree, architecture etc). This is a novel and unique feature of this system. Status and Availability The L1 sensor is fully operational on our M300 RTK aircraft and is ready for immediate deployment. Please see the 'Working With Us' section of this website and contact us to discuss your requirements. Working with Us This article was published on 2024-06-25
