Thermal-Mechanical Design and Detector Characterization of the Limb Imaging Fourier Transform Spectrometer Experiment

Abstract

The Limb Imaging Fourier Transform Experiment (LIFE) is a prototype of a satellite remote sensing instrument being developed at the University of Saskatchewan in collaboration with the Canadian Space Agency and ABB Inc. The prototype instrument is designed to take measurements of key atmospheric greenhouse gases on-board a high-altitude balloon gondola, to test the concept and provide insight towards future versions of the instrument. It will take measurements from the stratosphere, providing a vertical profile from the lower stratosphere to the upper troposphere, known as the UTLS region, an important region for understanding climate change. LIFE is conceptually similar to the Gimballed Limb Observer for Radiance Imaging in the Atmosphere (GLORIA), and aims to create a less expensive and smaller instrument to show that a cost-effective infrared Fourier Transform Spectrometer based atmospheric instrument is feasible. This thesis describes two main aspects of the LIFE prototype: The thermal-mechanical design and the characterization of the infrared detector. As a thermal imaging instrument, LIFE has strict thermal requirements and constraints in the harsh high-altitude environment. A thermal-mechanical design is developed and simulated to ensure that all requirements are met and the instrument will operate nominally during its high-altitude balloon flight. The infrared detector must be carefully characterized and optimized for the LIFE application through the altering and optimization of detector settings, to ensure that the measurements taken are of the best possible quality. The instrument successfully flew on its first test flight in Timmins, Ontario in August of 2019. All design requirements were met and the instrument operated nominally, taking numerous successful measurements of the UTLS. The goal of creating a design that would allow the survival and operation of the instrument in a high-altitude environment as well as the goal of optimizing the detector were both completed successfully. Overall, the goal of creating a low cost instrument that allows thermal emission measurements to be taken in the UTLS region was completed, and the knowledge gained from the project can be used to inform future improvements to the LIFE instrument.