The estimation of the Skyglow by using the nighttime light satellite imagery in Northern Thailand

Abstract

The skyglow is scattering from natural light sources and non-natural light, which maximizes night sky brightness, resulting in visual impairment and star visualization loss. This phenomenon leads to an impoverished environment and surroundings. SNPP - VIIRS Day/Night Band (DNB) is a source for monitoring skyglow phenomena and Nighttime Light (NTL) spatial expansion trend in northern Thailand. A scatter plot model was applied to the data. The sky brightness and radiance from SNPP-VIIRS exhibited R2 values of 0.9488. And the correlation of sky brightness in summer and winter had a value of 0.888. During summer, the Aerosol Optical Depth (AOD) value increased by 2.3-times and the natural sky rose to 1 times magnitude brighter than winter. In contrast, the amount of brightness in the city area decreased, resulting from the NTL released skyward by luminaires with aerosol particles, generating a luminous background. This research estimates and illustrating the skyglow map for a more straightforward astronomical interpretation. Consequently, Bortle's map and the skyglow profile are crucial research tools for monitoring light pollution and understanding the skyglow characteristics of skyglow which varies upon the specific AOD value, a substantial amount of aerosol and intensity of light directed upward.