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Generating Hemispherical Visualizations of Artificial Sky Brightness Using Updated Sky Glow Estimation Tools on Suomi NPP-VIIRS Data

The expansion of the global population in conjunction with rapid industrialization has caused an increase in artificial light pollution, also known as artificial sky glow. Anthropogenic light pollution disturbs the world's ecosystems by interfering with the interconnected life of flora and fauna, degrading night sky quality for astronomical and aesthetic viewing, and disrupting human circadian rhythms and melatonin production, which can have lasting negative effects on health. The Skyglow Estimation Toolbox (SET) calculates artificial sky glow by applying a model of light propagation to visible light radiance imagery from the Suomi National Polar-orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB). The previous iteration of SET was further expanded by adding a hemispherical visualization feature compiled from individual skyglow maps with different zenith/azimuth angle combinations at one location. The graphical user interface (GUI) of SET was also updated to include all functions of the command line interface, and the overall code repository now works with all versions of Python 2.7 and above. Written unit tests were installed to prevent future code breaks, and several issues were fixed such as logic errors, repository bloat, and lack of documentation. The revised SET was tested on four United States national parks to ensure functionality across different environments. The resulting hemispherical visualizations were provided to the National Park Service (NPS) to compare with in situ measurements. The team explored validation methods, which provided a basis for future action for measuring and managing light pollution around national park units.