Improve space positioning recognition of laser marker to promote the operating efficiency of Ground LiDAR—A case of FARO Photon 120

• Published in: Optics and lasers in engineering 2012-05, Vol.50 (5), p.731-735
• Main Author: Wu, Tsung-Chiang
• Format: Article
• Language: English
• Subjects: Clouds; Conjugated laser marker; Grounds; ISO11146 laser spot recognition formula; Lasers; LiDAR; Markers; Mathematical models; Point cloud; Recognition; Scanning
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/j.optlaseng.2011.11.015

Ground LiDAR scanning used in space operations, three or more conjugated laser markers between adjacent scanning stations are used to coordinate conversion and overlay of point cloud data, in order to get 3D point cloud model. The recognition of conjugated laser marker influences the precision of 3D point cloud model, and scanning distance is inversely proportional to the recognition. If scanning distance from LiDAR to laser marker is increased and the recognition of conjugated laser marker is maintained, it will promote the operating efficiency of Ground LiDAR. FARO Photon 120 and plane circular laser marker are studied in this research. Based on point cloud data features improved ISO11146 laser spot recognition formula, used to calculate laser marker center coordinate and diameter. The difference of calculated diameter minus actual diameter is the recognition of laser marker. The results show that laser marker 10–20cm in diameter is recognizable for 1cm or less than 30m scanning distance. The scanning distance is 30–50m, and laser marker 16–20cm in diameter is recognizable for 1cm or less. Therefore, increased diameter of laser marker helps in the recognition of laser marker of longer scanning distance. In Ground LiDAR operation, scanning distance from LiDAR to conjugated laser markers is increased by moderate increase in laser marker diameter. It will reduce scanning stations and shorten operation time and does not affect the accuracy of 3D point cloud model and promote the operating efficiency of Ground LiDAR. ► Cross and innovative applications. ► A ground Lidar quantization mode of scanning distance relationship with laser marker. ► Reduce scanning stations and keep work quality to effectively enhance ground Lidar applications. ► Provide important reference for similar research. ► Provide practical applications.