SkyGlow Model Successfully Applied to the Evaluation of the Light Pollution over Tucson, U.S.

The Slovak research team has developed a unique theoretical solution and an efficient software module for the calculation of the parameters of the light pollution in the dependence on current meteorological situation and the properties of light sources in the analysed region. The module is based on a smart algorithm that is able to do real-time calculations. In the comparison to alternative products it is ca 10 times faster at the same precision. This is one of the reasons why SkyGlow became the key tool for the prediction of the skyglow distribution under conditions where other solutions failed due to unacceptable demands on the computing power. SkyGlow was proved to be the only software module applicable in urban environment having high density and variability of light sources. In cooperation with Dark Sky Association and with representatives of the city of Tucson (U.S.) it was used for the forecast of changes in the diffuse light levels over Tucson after the extensive reconstruction of the public lighting system. SkyGlow solution was the basis for the judgment of the possible impacts of LED conversion in cities in U.S. (in charge of US Department of Energy and Pacific Northwest National Laboratory. This paper deals with the analysis of main results achieved by the modelling of the diffuse light levels of the night sky over Tucson and by utilizing terrestrial and satellite data. Experimental observations are also presented and analysed. The paper also shows the way how described methods can be used at the evaluation of possible changes in light pollution in other regions (including Czech Republic and Slovakia).