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Magnitude to luminance conversions and visual brightness of the night sky.
The visual brightness of the night sky is not a single-valued function of its brightness in other photometric bands, because the transformations between photometric systems depend on the spectral power distribution of the skyglow. We analyze the transformation between the night sky brightness in the Johnson-Cousins V band (m V , measured in magnitudes per square arcsecond, mpsas) and its visual luminance (L, in SI units cd m-2) for observers with photopic and scotopic adaptation, in terms of the spectral power distribution of the incident light. -
Artificial light at night (ALAN), blue light spectrum exposure and colorectal cancer risk in Spain (MCC-Spain study)
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Multispectral analysis of the night sky brightness and its origin for the Asiago Observatory, Italy
This study assesses the current state of the sky in the region through numerical modelling using the latest improvements to the ILLUMINA model and aims to identify the main contributing sources of artificial light. The explicit calculation of the contribution of private residential lighting helps to discern the origin of the light. We also present a new approach for extracting an estimate of the distribution of lamp technology in a region from images taken from the International Space Station. -
Evaluating Human Photoreceptoral Inputs from Night-Time Lights Using RGB Imaging Photometry
In this paper, we show that RGB imagery acquired with off-the-shelf digital single-lens reflex cameras (DSLR) can be a useful tool to evaluate, with reasonable accuracy and high angular resolution, the photoreceptoral inputs associated with a wide range of lamp technologies. The method is based on linear regressions of these inputs against optimum combinations of the associated R, G, and B signals, built for a large set of artificial light sources by means of synthetic photometry. Given the widespread use of RGB imaging devices, this approach is expected to facilitate the monitoring of the physiological effects of light pollution, from ground and space alike, using standard imaging technology. -
Colour remote sensing of the impact of artificial light at night (I): The potential of the International Space Station and other DSLR-based platforms
Here we describe a theoretical approach using colour-colour diagrams to analyse images taken by astronauts on the ISS to estimate spatial and temporal variation in the spectrum of artificial lighting emissions. We then evaluate how this information can be used to determine effects on some key environmental indices: photopic vision, the Melatonin Suppression Index, the Star Light Index, the Induced Photosynthesis Index, production of NO2-NO radicals, energy efficiency and CO2 emissions, and Correlated Colour Temperature. Finally, we use the city of Milan as a worked example of the approach. -
Modelling the night sky brightness and light pollution sources of Montsec protected area.
Lleida, the biggest city in the area, has been considered as the unique source of light pollution. In 2014 there was an update of the lighting infrastructure in Lleida. A detailed comparison of the sky brightness before and after the change is shown in order to measure the effects that different kind of lamps can produce. This information could be used to plan for future updates and improvements of the lighting systems in the area. -
New Features to the Night Sky Radiance Model Illumina: Hyperspectral Support, Improved Obstacles and Cloud Reflexion
In 2016-17, many improvements were made to the Illumina code including an overhead cloud scheme, an improved blocking scheme for subgrid obstacles (trees and buildings), and most importantly, a full hyperspectral modeling approach. Code optimization resulted in significant reduction in execution time enabling users to run the model on standard personal computers for some applications. After describing the new schemes introduced in the model, we give some examples of applications for a peri-urban and a rural site both located inside the International Dark Sky reserve of Mont-Mégantic. -
Evaluating the association between artificial light-at-night exposure and breast and prostate cancer risk in Spain (MCC-Spain study)
We evaluated the association of exposure to ALAN during sleeping time with breast and prostate cancer in a population based multicase-control study (MCC-Spain), among subjects who had never worked at night. We evaluated chronotype, a characteristic that may relate to adaptation to light at night. -
Modelling the effects of phosphor converted LED lighting to the night sky of the Haleakala Observatory, Hawaii
The goal of this study is to evaluate the current level of light pollution in the night sky at the Haleakala Observatory on the island of Maui in Hawaii. This is accomplished with a numerical model that was tested in the first International Dark Sky Reserve located in Mont-Mégantic National Park in Canada. -
Special issue of the Journal of Spectroscopoy and Radiative Transfer
Édition spéciale du journal sur le thème de la physique de la pollution lumineuse qui regroupe notamment plusieurs articles découlant des présentations faites au congrès « Light Pollution Theory Modeling and Measurement ». -
Special Issue on Light Pollution : Theory, Modelling, and Measurements (2019)
Un recueil d’articles scientifiques sur la thématique de la pollution lumineuse. -
Special Issue : Light Pollution Monitoring Using Remote Sensing Data
Un recueil d’articles scientifiques sur la thématique de la télédétection de la pollution lumineuse. -
Night sky brightness simulation over Montsec protected area
Night sky brightness over Montsec Observatory (north-east of Spain) has been computed and checked against measurements using Illumina numerical model [2]. In a previous publication [20] the methodology was validated and light pollution received in the observatory coming from a unique city was computed. Here we present a simulation that includes all the sources that has a significant impact over the quality of the night sky in this area. -
Restoring the night sky darkness at Observatorio del Teide: First application of the model Illumina version 2
In the past decades, the sky darkness was severely degraded by growing light pollution on the Tenerife Island. In this work, we use the contribution maps giving the effect of each pixel of the territory to the artificial sky radiance. We exploit the hyperspectral capabilities of Illumina v2 and show how the contribution maps can be integrated over regions or municipalities according to the Johnson-Cousins photometric bands spectral sensitivities. -
Commentary : Brightness of the night sky affects Loggerhead (Caretta caretta) sea turtle hatchling misorientation but not nest site selection
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On the relation between the astronomical and visual photometric systems in specifying the brightness of the night sky for mesopically adapted observers
In this work we deduce the transformation equations between the astronomical and visual photometric systems for specifying and reporting the sky brightness in the mesopic range, within the framework of the MES-2 system for visual performance-based mesopic photometry. -
Mapping the Melatonin Suppression, Star Light and Induced Photosynthesis Indices with the LANcube
In this paper, we suggest a method that allows high resolution mapping of the Artificial light at night by using ground-based measurements with the LANcube system. The device separates the light detected in four bands (Red, Green, Blue, and Clear) and provides this information for six faces of a cube. We found relationships between the LANcube’s colour ratios and 1- the Melatonin Suppression Index, 2- the StarLight Index and 3- the Induced Photosynthesis Index. We show how such relationships combined with data acquisition from a LANcube positioned on the top of a car can be used to produce spectral indices maps of a whole city in a few hours. -
Point spread functions for mapping artificial night sky luminance over large territories
Measuring the sky radiance can be a complex endeavour, depending on the desired temporal and spatial resolution. Likewise, the modelling of artificial night sky radiance for multiple points of a region can represent a significant amount of computing time depending on the complexity of the model used. The use of the convolution of a point spread function with the geographical distribution of light sources has been suggested in order to model the sky radiance over large territories of hundreds of kilometres in size. We determined how the point spread function is sensitive to the main driving parameters of the artificial night sky radiance, such as the wavelength, the ground reflectance, the obstacle properties, the upward light output ratio, and the aerosol optical depth using the Illumina v2 model.
