Design of the Birefringent Doppler Wind Imaging Interferometer instrument for the measurement of upper atmospheric winds

Abstract

This thesis presents the design of a ground-based instrument to measure atmospheric motions in Earth’s upper atmosphere using a spectrally isolated airglow emission. Building on a prototype developed at UNB, this work introduces several enhancements to improve performance in field applications. The primary focus is on optimizing the optical design to increase throughput while maintaining precision and stability. A Jones matrix model, implemented in Python, simulates signal and interference patterns to support the design process. Zemax OpticStudio is used to refine the optical layout and select appropriate lens configurations. Thermal sensitivity is addressed by investigating the use of birefringent materials with inverse thermal coefficients for interferometer compensation. Experimental results demonstrate the feasibility of using αBBO and YVO4 crystals in a thermally compensated, field-widening interferometer. Additional designs, including various lenses and a four-quadrant prism, are explored to expand the field of view without compromising measurement accuracy.