Precision Analysis of the Underwater Laser Scanning System to Measure Benthic Organisms

In order to realize high-speed and large-scale three-dimensional measurement of benthic organisms, the underwater laser scanning system is designed. First, a mathematical model of the underwater imaging is established, which can express the light propagation, light refraction, and the transformation between the pixel and the light. Then, the precision analysis of the underwater laser scanning system is studied. The effect of the camera’s lens, focal length and baseline distance on the precision of 3D reconstruction is analyzed. Finally, the system calibration is carried out and the precision of the underwater laser scanning system is verified with the standard targets whose distance are known before. The experiment of the precision evaluation with the ball bar shows that the RMS of the system can achieve 0.87 mm, when the depth is between 2 m and 3 m.