Design of a hyperspectral imaging gonioradiometer for appearance characterization

Area of Science:

• Optical Engineering
• Surface Metrology
• Spectroscopy

Background:

• Bidirectional Scatter Distribution Function (BSDF) describes surface optical scatter properties.
• Existing instruments primarily measure BSDF for flat, uniform surfaces.
• Characterizing non-flat surfaces with spatially variant reflectance is challenging.

Purpose of the Study:

• To develop and present an instrument for measuring spectral, spatially variant BSDF of non-flat surfaces.
• To adapt existing BSDF measurement systems for advanced surface characterization.
• To enable detailed spectral reflectance data collection for complex geometries.

Main Methods:

• Incorporation of a snapshot hyperspectral camera into an existing BSDF measurement system.
• Utilizing a plenoptic acquisition method for non-flat surface measurements.
• Addressing challenges in zooming and focusing on three-dimensional objects.

Main Results:

• Demonstration of an instrument capable of determining spectral, spatially variant BSDF.
• Detailed spectral reflectance data acquisition for each pixel.
• Successful characterization of samples with spatially variant reflectance properties.

Conclusions:

• The refurbished instrument effectively measures spectral, spatially variant BSDF on non-flat surfaces.
• Hyperspectral imaging and plenoptic methods enhance surface characterization capabilities.
• The system offers a novel approach for analyzing complex optical scatter properties.