Testing sky brightness models against radial dependency: a dense two dimensional survey around the city of Madrid, Spain

Abstract

We present a study of the night sky brightness around the extended metropolitan area of Madrid using Sky Quality Meter (SQM) photometers. The map is the first to cover the spatial distribution of the sky brightness in the center of the Iberian peninsula. These surveys are neccessary to test the light pollution models that predict night sky brightness as a function of the location and brightness of the sources of light pollution and the scattering of light in the atmosphere. We describe the data-retrieval methodology, which includes an automated procedure to measure from a moving vehicle in order to speed up the data collection, providing a denser and wider survey than previous works with similar time frames. We compare the night sky brightness map to the nocturnal radiance measured from space by the DMSP satellite. We find that i) a single source model is not enough to explain the radial evolution of the night sky brightness, despite the predominance of Madrid in size and population, and ii) that the orography of the region should be taken into account when deriving geo-specific models from general first-principles models. We show the tight relationship between these two luminance measures. This finding sets up an alternative roadmap to extended studies over the globe that will not require the local deployment of photometers or trained personnel.

Journal of Quantitative Spectroscopy & Radiative Transfer December 21, 2015

References in corpus (4)

• The new world atlas of artificial night sky brightness
• Contributions of artificial lighting sources on light pollution in Hong Kong measured through a night sky brightness monitoring network
• The Dancing Sky: 6 years of night sky observations at Cerro Paranal
• Evolution of the energy consumed by street lighting in Spain estimated with DMSP-OLS data

Cited by in corpus (9)

• The new world atlas of artificial night sky brightness
• Sky Quality Meter measurements in a colour changing world
• The nature of the diffuse light near cities detected in nighttime satellite imagery
• Imaging and mapping the impact of clouds on skyglow with all-sky photometry
• Estimating the relative contribution of streetlights, vehicles and residential lighting to the urban night sky brightness
• Mapping the brightness and color of urban to rural skyglow with all-sky photometry
• Light pollution offshore: zenithal sky glow measurements in the Mediterranean coastal waters
• The Temporal Analysis of Light Pollution in Turkey using VIIRS data
• Characterizing the zenithal night sky brightness in large territories: How many samples per square kilometer are needed?