DESIGN OF A LOW-COST PORTABLE HANDHELD SPECTROMETER FOR AEROSOL OPTICAL DEPTH MEASUREMENTS

The impact aerosols have on human health and the climate continues to be a central topic in scientific research. The quantification of aerosol abundance in the atmosphere is a key factor in understanding the climate, Earth’s radiative budget, and their impacts to human health. This research focuses on the development and comprehensive assessment of a handheld field instrument that measures aerosol optical thickness. The challenges associated with designing a low-cost, durable handheld system with highly sensitive electronics, which is capable of direct-sun measurements, are investigated. The thesis work can be summarized as follows. First, the electrical, mechanical, and optical integration needed for the instrument development is discussed and presented. Second, the sensitivities of a compact micro spectrometer are analyzed in both the laboratory and field deployment studies. The spectrometer and the fully integrated instrument are characterized in terms of its spectral resolution, sensitivity, thermal characteristics, and stability. Finally, after successful performance characterization, the capabilities of the instrument for field measurements are explored by taking direct sun measurements. The results demonstrate that the instrument has great potential to be used as a rigorous scientific device or a citizen science, educational instrument for aerosol optical depth measurements