A new method of measuring and monitoring light pollution in the night sky

Abstract

This paper describes a method of measuring and monitoring light pollution in the night sky. This method is capable of instantly quantifying the levels of artificial radiance and monochromatic luminance of the sky glow by means of a system that includes an all-sky camera as well as several interference filters. The calibration is done with an integrating sphere where the measurement pattern used is obtained from the light reflected from the inner wall of the sphere which comes from radiation emitted by a calibration lamp with a known luminous flux. The inner wall of this sphere is a Lambertian surface, which ensures that the light reflected or falling on it is uniformly dispersed in all directions (i.e. the surface luminance is isotropic).