The emission function of ground-based light sources: State of the art and research challenges

• Published in: Journal of quantitative spectroscopy & radiative transfer Vol. 211; pp. 35 - 43
• Main Author: Solano Lamphar, Héctor Antonio
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2018
• Subjects: Light pollution; Skyglow; The emission function; The emission function; Light pollution; Skyglow
• ISSN: 0022-4073; 1879-1352
• DOI: 10.1016/j.jqsrt.2018.02.034

•The importance of the emission function in modelling skyglow is discussed.•The research challenges on the retrieval of the emission function are stated.•The literature on the emission function previously published is reviewed To understand the night sky radiance generated by the light emissions of urbanised areas, different researchers are currently proposing various theoretical approaches. The distribution of the radiant intensity as a function of the zenith angle is one of the most unknown properties on modelling skyglow. This is due to the collective effects of the artificial radiation emitted from the ground-based light sources. The emission function is a key property in characterising the sky brightness under arbitrary conditions, therefore it is required by modellers, environmental engineers, urban planners, light pollution researchers, and experimentalists who study the diffuse light of the night sky. As a matter of course, the emission function considers the public lighting system, which is in fact the main generator of the skyglow. Still, another class of light-emitting devices are gaining importance since their overuse and the urban sprawl of recent years. This paper will address the importance of the emission function in modelling skyglow and the factors involved in its characterization. On this subject, the author's intention is to organise, integrate, and evaluate previously published research in order to state the progress of current research toward clarifying this topic.