OpTeC Colloquium

OpTeC sponsors a colloquium throughout the academic year. This is a forum where a wide range of optical science and engineering topics are discussed at a level that can be understood by a broad spectrum of optics students, staff, and faculty. The primary purposes are to train students to give effective scientific talks and to promote cross-disciplinary interactions of students, staff, faculty, and local industry employees. Speakers include MSU students, staff, and faculty, and visitors from external universities, research labs, and companies.

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Thursday, February 20, 2025 at 4:10 pm.

Norm Asbjornson Hall, Room 153

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Tracking the sky’s neutral point positions for atmospheric turbidity

Meredith Kupinski, Ph.D.
Associate Professor of Optical Sciences
Wyant College of Optical Sciences
The University of Arizona

Abstract

Monitoring the polarization signature of the sky is valuable for navigation, meteorology, and remote sensing. However, the neutral points—Babinet (above the Sun), Brewster (below the Sun), Arago (above the anti-Sun), and the Fourth (below the anti-Sun) — remain underutilized as meteorological tools. Unlike direct line-of-sight measurements, neutral point positions are influenced by scattering throughout the sky dome. The neutral points are randomly polarized due to an incoherent balance of single and multiple scattering, but further research is needed to understand their positional changes under varying atmospheric conditions. In this talk, I will share the development of the Ultraviolet Linear Stokes Imaging Polarimeter (ULTRASIP), designed to image the sky with a 7.2 arcseconds/pixel resolution at a center wavelength of 355 nm (20 nm bandpass). We have developed an original estimation technique that achieves Babinet altitude uncertainties ranging from 2.16 to 5.40 arcseconds over a day-long observation period. The development of ULTRASIP and high-precision neutral point tracking will facilitate correlation studies with Aerosol Robotic Network (AERONET) atmospheric turbidity data, enhancing our understanding of sky polarization applications.

Biographical Sketch

Meredith Kupinski joined the Wyant College of Optical Sciences at the University of Arizona (UA) in 2008 where she is now an Associate Professor developing polarimetric instrumentation, polarized light scattering models, and polarization-aware computer vision and graphics capabilities. Prof. Kupinski was the recipient of a Science, Engineering, and Education for Sustainability (SEES) postdoctoral NSF fellowship to study polarimetry for aerosol science. In 2016, she was awarded a Jean d’Alembert visiting scholar position at École Polytechnic in France to work on Mueller polarimetry for cervical cancer detection. She recently received an NSF CAREER award to develop polarimetric importance sampling for computer graphics. She is the PI of a NASA Instrument Incubator Program on Channeled Infrared Polarimetry for cloud ice observations. She is also the PI of an ONR project on manifold optimization to use quadratic imaging statistics in detection problems. She earned a BS with Highest Honors in Imaging Technologies from the Rochester Institute of Technology and an MS and PhD in Optical Sciences from UA.

Past Speakers