Hesai Technology XT32

The Hesai Technology XT32 is a spinning LiDAR from China for mid-range distances, used on mid-sized multicopters. It is a scanner without its own position determination and is built into survey payloads by system suppliers.

The scanner rotates and covers 360 × 31°; 32 channels, meaning 32 lasers, capture stacked lines. It produces 640,000 points per second with one echo and reaches 120 m. Accuracy is quoted as ±1 cm, precision as 0.5 cm (1 sigma): accuracy means the deviation from the true value, precision the repeatability of the measurement. Both figures are comparable only with like-defined figures. The unit weighs 800 g. The XT32M2X variant sits in the YellowScan Surveyor Ultra and is not identical to the XT32.

The XT32 contains lasers and is therefore a laser device; the laser class given by the manufacturer is to be observed. The weight counts towards the take-off mass of the aircraft, whose EU class limits are 900 g (C1), 4 kg (C2) and 25 kg (C3 and C4). Point clouds of built-up areas can make people and property recognisable, and then data-protection law applies.

Georeferenced data requires an IMU and a GNSS, which for a plain scanner come from outside; the quality of the point cloud then hinges on the synchronisation of scanner and positioning system. A spinning sensor has a motor with bearings, which counts as a wear part, and a window on which dirt settles. The mount must be rigid and low-vibration so that the alignment to the positioning system stays stable.