LIGHT POLLUTION MODELLING THE UK HIGHWAYS AGENCY NEW ENVIRONMENTAL POLICY, INC. ASTRONOMICAL IMPACT OF BLUE-RICH LED LUMINARIES

摘要

The Highways Agency are replacing their policy of full cut off class G6 road lighting specification on motorways, and are adopting a categorised environmental impact based point system that can accommodate technical advances, such as LED lighting. The Sky glow component of this will be based on the modelling of sky glow versus cut-off angle, developed for determining the relative light pollution environmental impact of different streetlight designs. Further modelling has been done concerning the effect of LED lighting, which potentially, has highly directional properties. But increasingly used blue rich colour temperatures are likely to increase sky glow by at least 5 fold, compared to traditional lighting. This is due to enhanced reflection of vegetation and greatly increased atmospheric molecular Rayleigh scattering. This is a potential astronomical environmental disaster in the making. The paper also describes the results from the same model adapted to study the night-time environmental impact of a proposed wind farm project as a part of the planning process. It would have many navigation and aviation warning lights on the turbine masts, covering a grid of over 10 km a side, which would be visible from the adjacent coast some 15 km away. The results are compared with a typical dark rural environment.