Joe Kurtz, University of New South Wales – Canberra; Andrew Jolley, Western Sydney University; Scott Tyo, University of New South Wales – Canberra
Keywords: solar panel, light scattering, polarimetry
Abstract:
The scattering of incoherent light by a small solar panel of the type used on cubesats was measured in the visible wavelength region in terms of its Mueller matrix. The light source used was wavelength-resolved by a monochromator with additional optics for generating a complete set of stokes vectors. The detector was a polarimetric camera used with additional optical components for complete stokes-vector characterization of the scattered light. The results were the sample’s Mueller matrix resolved to wavelength and scattering angles near specular. These results were processed to compare to similar data taken on a different experimental apparatus using broadband wavelength filters with an event-based camera detector. The aim of these and other measurements of typical spacecraft materials is to provide data as input to modelling that can help identify and discriminate orbital objects by their reflected light signatures.
The measurement apparatus (referred to as the ‘Polarimetric Scatterometer’) is a facility of the Advanced Sensors Laboratory at the University of New South Wales – Canberra, Australia. It consists of multiple motorized stages configured to arrange a sample, light source, and detector/imager to enable taking angle- and wavelength-resolved scattering measurements from the sample in an arbitrary scattering plane. The addition of polarizing optics to the source and detector enables the measurement of the complete 4×4 Mueller matrix of the sample at any given angle and (visible) wavelength. The light source, detector/imager, any rotatable optics, and all stages (sample orientation) are controlled by a single laptop computer which also records the data via Matlab scripts. A Matlab simulator has also been written to aid measurement setup and execution by applying stage-control scripts to a virtual scatterometer before the experimental measurements are attempted. The simulator provides a visualization of the measurements that helps the experimenter set the correct control parameters before taking a set of measurements. The same control scripts are then used for the actual measurements. The scripts can run without an operator being present as highly resolved measurements can take a few hours to complete.
Date of Conference: September 14-17, 2021
Track: Non-Resolved Object Characterization