Light pollution analysis and future prediction of world astronomy sites with urban development model and VIIRS-DNB satellite data

The aim of this thesis is to determine the artificial light effect in the near future (2030) at 84 professional astronomy sites with telescopes with a mirror diameter of 1 m and above in the world by using satellite and model data with Remote Sensing (RS) and Geographic Information Systems (GIS) methods. With VIIRS-DNB satellite data, the current artificial light status of astronomy sites for 2012-2023 was evaluated and statistics (regression, correlation, Mann-Kendall and Sen's-Slope) were calculated for the data set. The annual average light pollution of astronomy sites is 19.2 𝑚𝑎𝑔/𝑎𝑟𝑐𝑠𝑒𝑐2, of which ~12% (10 astronomy sites) are below the average, these astronomy sites have more light pollution than the others. The urbanisation of astronomy sites was determined using an urban development model for the distant future (2050). The temporal change of artificial light for six astronomy sites selected from different locations was modelled by regression analysis together with the urban model outputs and predicted for the near future (2030). After the artificial light map for the year 2030 obtained from the urban development model and regression analysis for these six astronomy sites, the Inverse Square Law was used to determine the artificial light affecting the astronomy sites. For the year 2023, the existing and predicted artificial light effect was compared and the 𝑎𝑡 coefficient that establishes the connection between these two results was calculated. 𝑎𝑡 coefficient was found to show a significant relationship at a level of ± 0.80 and above in at least one of the Spearman, Pearson and Kendal correlations with the number of pixels in the high probability classes of 2030 and some parameters that are model outputs. A linear equation was obtained between these parameters and 𝑎𝑡 coefficient and 𝑎𝑡 coefficient was calculated for all astronomy sites. It was found that the artificial light effect at the six astronomy sites varied between 13% decrease and 110% increase compared to 2023.