3D scanning accuracy varies by equipment and method:
Survey-Grade Terrestrial Scanners: Trimble X12, Leica RTC360, and FARO Focus Premium achieve ±1-2mm accuracy at typical working distances. These are used for high-precision applications like industrial metrology, survey control, and engineering documentation.
Mobile Mapping Systems: NavVis VLX3 and Leica BLK2GO achieve ±5mm accuracy (±3mm with control points). These trade some precision for 10-20x faster capture speeds, ideal for large facility documentation.
Drone Photogrammetry: With proper ground control points, drone mapping achieves ±2-3cm horizontal and vertical accuracy. This is sufficient for topographic mapping, construction monitoring, and volumetric calculations.
Drone LiDAR: Professional systems like ROCK R3 Pro achieve ±2cm vertical accuracy, enabling survey-grade deliverables for large areas including vegetation-covered terrain.
The key is matching equipment to accuracy requirements—over-specifying accuracy increases cost without benefit.