Underwater galvanometer 3D scanning system based in turbid water: imaging model, adaptive exposure algorithm, and...

Area of Science:

• Optics and Photonics
• Robotics and Automation
• Marine Technology

Background:

• High-precision 3D imaging in turbid water is challenging due to light scattering.
• Lasers offer unique properties like monochromaticity and coherence for underwater applications.
• Existing underwater scanning technologies struggle with varying turbidity levels.

Purpose of the Study:

• To investigate laser imaging characteristics in diverse turbid water conditions.
• To develop an adaptive algorithm for enhanced underwater 3D laser scanning.
• To evaluate the accuracy and performance of a custom-built underwater laser scanner.

Main Methods:

• A custom galvanometer-based underwater 3D laser scanner was designed and implemented.
• A line laser imaging model was established to analyze laser behavior in turbid water.
• An adaptive laser image exposure algorithm was developed and integrated into the scanning system.

Main Results:

• The study established a laser imaging model for varying turbidity.
• An adaptive exposure algorithm was proposed and validated.
• Sub-millimeter 3D scanning accuracy was achieved at a 1000 mm working distance.
• The system demonstrated effectiveness within a turbidity range of 10 NTU.

Conclusions:

• The developed underwater 3D laser scanner and adaptive algorithm significantly enhance imaging precision in turbid environments.
• The technology shows promise for applications requiring accurate 3D reconstruction underwater.
• Sub-millimeter accuracy is achievable in challenging, turbid water conditions.