Split-screen, single-camera, laser-matrix, stereogrammetry instrument for topographical water wave measurements

Area of Science:

• Fluid Dynamics
• Optical Measurement Techniques
• Wave Physics

Background:

• Accurate water wave surface topography measurement is crucial for understanding wave dynamics.
• Traditional stereogrammetry requires identifying key features from multiple viewpoints, which can be challenging for dynamic surfaces like water waves.

Purpose of the Study:

• To develop and demonstrate a new technique for water wave shape measurement using stereogrammetry.
• To overcome limitations of conventional feature identification in wave topography analysis.

Main Methods:

• A holographic lenslet array was used to generate a matrix of laser beams from a single source.
• These beams created a matrix of highlights on the water wave surface.
• Stereogrammetry techniques were applied to calculate the surface shape from the highlight matrix, utilizing a split-screen viewing system for simultaneous multi-angle observation with a single camera.

Main Results:

• The technique successfully generated a highlight matrix on the water wave surface.
• Stereogrammetry was effectively employed to determine the water wave's surface shape from the highlight pattern.
• A laboratory demonstration validated the feasibility of the proposed method.

Conclusions:

• The holographic lenslet array technique provides a viable method for water wave surface topography measurement.
• This approach simplifies feature identification for stereogrammetry, enhancing accuracy and efficiency.
• The method shows potential for adaptation to field conditions for real-world wave studies.