2018 schedule

Bendigo:- A case study in LED streetlights and light pollution.

Mike Chapman

Sydney Outdoor Lighting Improvement Society

Light emitting diode (LED) technology has brought significant innovation to the lighting industry. The benefits of high efficacy LED street lighting has encouraged government sponsored programs to reduce power consumption, lower maintenance costs, reduce greenhouse gas emission and reduce sky glow. In the case of sky glow and light pollution there are no standardised or quantitative method of measurement. Some controversy such as health aspects as cited by the American Medical Association (AMA) exist around these refit programs. Presented here is the result of a time series
analysis of data from the Suomi/VIIRS satellite from South-East Australia where LED street lights replaced mercury vapour and compact fluorescent lighting. A town in Victoria, Australia, Bendigo is selected as a case study of radiance. Using a simplified inventory of the prior street lighting the total luminous flux of the lighting inventory is compared to the radiance images from Suomi Day/Night Band (DNB) and compared to the expected results of the sky-glow modelling software Illumina. Discussion is focussed on the use of the Suomi/DNB sensor as a detector and as an estimator of light pollution. Using a simplified model of light in the atmosphere this paper suggests the short wavelength spectral component of the LED luminaires remains in the lower atmosphere and that a greater component of this blue spectrum than the original lighting inventory is produced in the wavelength range specified by the AMA as a blue light hazard.