Physics & Engineering Physics Colloquium

Emily Shipley, FCRH ’20, engineering physics major, will present, “Morphological Discrimination and Classification of Complex Aerosol Aggregates via Simulated Two-Dimensional Multi-Spectral Light Scattering.”

Light scattering patterns from non-spherical particles and aggregates are a complex speckle pattern resulting from the interference among the constituent particles. The variation in in the observed patterns vary from particle to particle and from forward and backward scattering. Previous experimental work indicated that some features in the scattering patterns can reflect aggregate morphology and are useful for classifying particle types. Despite past success, these studies have used a limited data set, and the aerosol morphology was not well characterized. Promising experimental results have prompted a more extensive study that better controls the aggregate parameters. In this study, light scattering simulations have been performed across multiple wavelengths, and the resulting patterns have been analyzed to produce morphological descriptors that reflect particle characteristics. As a result, the identified morphological descriptors may be employed in multivariate statistical algorithms of “unknown” particle classification. These descriptors are processed using a multivariate statistical algorithm and the controlled particles are classified. This talk will focus on the descriptors and their relation to the simulated aggregates, and how the multispectral information may be used for classifying various particle types including those of biological origin.