Underwater 3D Surface Measurement Using Fringe Projection Based Scanning Devices

Area of Science:

• Optical engineering
• Robotics
• Marine technology

Background:

• Underwater 3D surface measurement is challenging due to optical distortions.
• Existing fringe projection techniques require adaptation for submerged use.

Purpose of the Study:

• To adapt fringe projection for underwater 3D surface measurements.
• To develop an effective calibration procedure for underwater stereo scanners.
• To demonstrate a new underwater 3D scanning device.

Main Methods:

• An extended camera model accounting for refraction.
• A combined air-to-water calibration technique using pinhole and ray-based modeling.
• Development of a compact, submersible fringe projection scanner.

Main Results:

• The proposed calibration is effective with minimal underwater recordings.
• The new device weighs 10 kg, operates up to 40 m depth.
• Achieved lateral resolution of 150 μm within a 0.33-second scan time.

Conclusions:

• The fringe projection technique is viable for underwater 3D surface measurement.
• The developed calibration and device enable efficient and accurate submerged scanning.
• This technology advances marine exploration and underwater inspection capabilities.