In preparation for the Zenmuse L3 product launch, I invited Christian Stalling, CP (Certified Photogrammetrist), from the U.S.-based surveying firm Vertical Aspect, to independently evaluate the accuracy performance of the Zenmuse L3 LiDAR when paired with the Matrice M400. Because FAA Part 107 regulations restrict most commercial operations to 400 ft or 120 m AGL without a waiver, the study was intentionally designed around the altitude ranges where the majority of real-world L3 missions will be flown. Rather than testing the sensor under ideal high-altitude conditions near its 950 m detection capability, the goal was to determine how well it performs under the actual constraints faced by everyday operators.
To achieve this, Christian developed a rigorous, controlled test program aligned with ASPRS accuracy standards. The evaluation emphasized realism: all accuracy measurements were taken directly from DJI Terra’s native point cloud output, without cleanup or enhancement through third-party processing, ensuring the results reflect a typical user workflow. Each flight followed repeatable, standardized procedures to ensure the findings were objective, consistent, and representative of professional surveying operations.
Flight Preparation
To isolate the performance variables, Christian and the team conducted repeated flights over the same test area using the same flight boundary KML, scan mode, scan overlaps ratio, maximum number of returns avaliable and PPK correction source. Across these missions, they systematically varied sampling rate, and AGL height to build a complete test matrix. The primary goal was straightforward: confirm that the Zenmuse L3 can deliver reliable vertical accuracy at or below 400 ft AGL, even under different operational configurations.
M400 and Zenmuse L3 Test Unit
To accurately quantify the combined system error of the Zenmuse L3 and the Matrice 400 airframe, it is essential to establish a controlled test environment with high-accuracy ground checks. The validation check shots must exhibit smaller precision errors than the target objects being evaluated; otherwise, the resulting statistics would be influenced by control uncertainty and fail to represent the true total measurement error of the system.
For the check shots: Christian and the team established a network of 30 elevation checkpoints following the ASPRS Positional Accuracy Standards. These points were collected using a Carlson BRx7 GNSS receiver, with each checkpoint measured twice to confirm horizontal repeatability. All measurements were collected over a VRS connection with an approximate 5-mile baseline, and each observation was recorded over 30 epochs to ensure stability. Elevations were further refined using a closed optical leveling loop, achieving ground-truth accuracy within approximately one-thousandth of a foot (0.03 cm).
These 30 checkpoints served exclusively as validation points. No ground control points were used at any stage of the L3 accuracy testing to avoid influencing the system-level error assessment.
Check Point Distribution
Example of a Check Point
The accuracy evaluation showed that the Zenmuse L3 consistently achieved survey-grade performance across all missions flown at or below 400 ft AGL. The native point clouds produced directly in DJI Terra required no cleanup, filtering, or specialized post-processing, yet still delivered strong accuracy.
Accuracy Test Results
Zenmuse L3 Accuracy Analysis and Use Case Exploration
The accuracy validation was conducted in a parking lot environment with a hard, uniform asphalt surface and no vegetation canopy. This test scene was intentionally selected by team to eliminate environmental variables such as vegetation penetration, soft terrain deformation, or canopy-related noise. With external factors minimized, the resulting measurements isolate the true performance of the M400 and Zenmuse L3 system.
"Across all tests, the DJI Zenmuse L3 consistently achieved sub-centimeter vertical accuracy and sub-1.5-centimeter 3D accuracy, with no meaningful dependency on PRF, altitude, or point density. The absence of correlation between acquisition parameters and measured accuracy demonstrates high system calibration, low boresight error, and robust GNSS/IMU integration. In practical terms, these results confirm that the Zenmuse L3 delivers high absolute accuracy that will meet most intended use cases." - Christian Stallings, Vertical Aspect
For professionals working in construction, surveying, AEC, utilities, or environmental monitoring, these results provide clear assurance that the L3 can meet demanding survey-grade accuracy requirements without relying on additional processing pipelines or specialized configurations. The consistency demonstrated across all test cases indicates that users can expect predictable, dependable accuracy even as typical mission parameters, such as altitude or sampling rate, vary within the 120 m (400 ft) operational limits.