Mapping light pollution with integrated indicators derived from all-sky hemispheric radiance data

Abstract

It has been calculated in up to one million directions in the sky the radiance produced by a single source of light in the 0.12 km - 527 km range and for different light source and observing site altitudes. Using these data, light pollution indicators’ discrete Point Spread Functions (PSF) were computed: radiance averaged over all the hemisphere, at 30° altitude, in the first 10° above the horizon, and horizontal irradiance. From the discrete PSFs, analytical PSFs were retrieved, permitting to obtain the indicators values in a much faster way compared to the traditional path, with saving times of the order of 10⁴-10⁶. As applications, it has been evaluated the light pollution at all the world’s major professional astronomical observatories and maps of Iberian peninsula for all the studied indicators were produced.