Papers by Pierantonio Cinzano
Monthly Notices of the Royal Astronomical Society
Light pollution at astronomical observatories is one of the main factors to be taken into account... more Light pollution at astronomical observatories is one of the main factors to be taken into account to preserve their scientific productivity and their useful lifetime. Using the Garstang–Cinzano model applied to the Visible Infrared Imaging Radiometer Suite (VIIRS) 2021 satellite radiance data, we have compared 28 sites, all hosting telescopes with apertures larger than 3 m, plus some additional selected sites. We computed and analysed five indicators of light pollution: radiance at zenith; averaged at 60° zenith distance; averaged over all the sky; averaged in the first 10° above the horizon; and horizontal irradiance. We found large variations of the values of the indicators, with a factor greater than 600 for the zenith artificial radiance between the least and most polluted major observatories. The results show that two-thirds of all large observatories have already surpassed the critical 10 per cent increase in radiance over the assumed natural levels. The results presented and ...
Nature Astronomy
Unfettered access to dark night skies is rapidly diminishing, due to light pollution and satellit... more Unfettered access to dark night skies is rapidly diminishing, due to light pollution and satellite constellation tracks. Scientists should do more to stand up to 'big light' and 'big space' and preserve this natural resource.
Transactions of the International Astronomical Union, 2002
These are maps of artificial night sky radiance that were produced by the Light Pollution Science... more These are maps of artificial night sky radiance that were produced by the Light Pollution Science and Technology Institute (ISTIL), and described in the paper "The New World Atlas of Artificial Night Sky Brightness" (Falchi et al. 2016). The data are stored in a 2.9 Gb geotiff file, on a 30 arcsecond grid. The map reports simulated zenith radiance data in [mcd/m^2]. The map is based on data from the VIIRS Day Night Band (DNB, MIller et al. 2013), which has been propagated through the atmosphere using the radiative transfer code reported in (Cinzano and Falchi, 2012). The upward emission function and the radiance calibration were obtained using data from Sky Quality Meters (including data from Duriscoe et al. 2007; Falchi 2010; Kyba et al 2013, 2015 and Zamorano et al. 2016). Note that the maps report artificial light only! The zenith radiance from natural sources such as stars and the Milky Way are not included, and must be added in order to match the data that would be ob...
Notes importantes concernant ce document Ceci est une traduction de l'anglais réalisée par Alexis... more Notes importantes concernant ce document Ceci est une traduction de l'anglais réalisée par Alexis Bosson 1 et Mireille Sanchez Arias 2 pour l'Association Nationale pour la Protection du Ciel Nocturne 3 avec l'aimable autorisation des auteurs. Cette traduction a été réalisée dans un but strictement informatif afin de permettre aux lecteurs francophones d'accéder à cet Atlas. En aucun cas, cette traduction ne saurait remplacer le document original, dont la rigueur scientifique assure l'exactitude des termes employés, qui peuvent avoir été incorrectement transcrits dans le présent document, malgré les soins apportés. Nous invitons donc le lecteur à consulter le document original "The First World Atlas of the artificial night sky brightness"ainsi que les cartes à haute résolution sur le site internet du professeur Pierantonio Cinzano : http://www.lightpollution.it/worldatlas/ Résumé Nous présentons le premier Atlas Mondial de la clarté artificielle du ciel nocturne, au zénith, convertie au niveau de la mer. Basé sur les données étalonnées du rayonnement prises à haute résolution par le satellite DMSP et sur la modélisation précise de la propagation de la lumière dans l'atmosphère, il fournit une représentation presque mondiale de la façon dont l'humanité est en train de s'envelopper dans un brouillard lumineux. En comparant l'Atlas avec la base de données de la densité de population du Ministère de l'Énergie Américain ("U.S. Department of Energy = DOE") nous avons déterminé la fraction de la population vivant sous un ciel d'une certaine clarté. Environ deux tiers de la population mondiale et 99% de la population des État-Unis (hors Alaska et Hawaï) et de l'Union Européenne vivent dans des régions où le ciel nocturne dépasse le seuil fixé pour le statut de ciel pollué. En considérant une acuité visuelle moyenne, environ un cinquième de la population mondiale, plus des deux tiers
Symposium - International Astronomical Union, 2001
We present maps of the artificial sky brightness in Europe in V band with a resolution of ~1 km. ... more We present maps of the artificial sky brightness in Europe in V band with a resolution of ~1 km. The aim is to understand the state of night sky pollution in Europe, to quantify the present situation and to allow future monitoring of trends. For each terrestrial site the artificial sky brightness in a given direction on the sky is obtained by integrating the contributions from each surface area in the surroundings, using detailed models of the propagation in the atmosphere of the upward light flux emitted by the area. The top-of-atmosphere light flux is measured by the Operational Linescan System of the Defence Meteorological Satellite Program (DMSP) satellites. The modelling technique, which was introduced and developed by Garstang, takes into account the extinction along light paths, double scattering of light from atmospheric molecules and aerosols, and Earth curvature. Use of this technique allows us to assess the aerosol content of the atmosphere.
Memorie Della Societa Astronomica Italiana, Apr 1, 2003
We present a method to evaluate the artificial night sky brightness across the entire sky at any ... more We present a method to evaluate the artificial night sky brightness across the entire sky at any site of the World for given atmospheric conditions and accounting for mountain screening, elevation and Earth curvature. The method is an extension of the modelling technique developed by Roy Garstang and extended by Cinzano, Falchi, Elvidge & Baugh and Cinzano, Falchi & Elvidge with the use of satellite radiance measurements at visible wavelength.
The world-wide problem of increasing light pollution is assessed through the development of globa... more The world-wide problem of increasing light pollution is assessed through the development of global maps of the distribution of zenith sky brightness with a resolution of approximately 1 km. These maps are produced using satellite imagery which provides photometrically calibrated data over the surface of the Earth at night, combined with a model of light scattering in the atmosphere to calculate the sky brightness from a given location. High resolution upward flux data have been obtained from the Operational Linescan System carried by the Defense Meteorological Satellite Program satellite, an oscillating scan radiometer with low-light visible and thermal infrared imaging capabilities. Light propagation in the atmosphere was computed at sea level based on the modeling technique introduced by Garstang which account for Earth curvature, double scattering and extinction. The Atlas reveals that light pollution of the night sky is not confined, as commonly believed, to developed countries,...
Light Pollution: The Global View, 2003
ABSTRACT We present the global monitoring of light pollution, night sky brightness and stellar vi... more ABSTRACT We present the global monitoring of light pollution, night sky brightness and stellar visibility carried on by our group based on DMSP satellite data and we describe the products obtained. We summarise the situation of the artificial night sky brightness in the World and we present a map of the night sky brightness in Chile taking into account the altitude of the observing site and simple projections to the year 2025 under two possible scenarios.
Astrophysics and Space Science Library, 2003
We present preliminary results of the application of the night sky brightness modelling technique... more We present preliminary results of the application of the night sky brightness modelling technique developed by Roy Garstang and extended by Cinzano, Falchi, Elvidge & Baugh and Cinzano, Falchi & Elvidge to high-resolution DMSP-OLS satellite measurements of upward artificial light flux with the aim of predicting the brightness distribution of the night sky in the astronomical photometric bands at any given site. This method, based on global data and accounting for mountain screening, elevation and the Earth’s curvature, allows the evaluation of the sky glow over the entire sky at any site of the world for given atmospheric conditions.
We present a portable automatic instrument for monitoring night sky brightness and atmospherical ... more We present a portable automatic instrument for monitoring night sky brightness and atmospherical transparency in astronomical photometrical bands. Main requirements were: fast and automatic coverage of the entire sky, lightness, transportability and quick set-up in order to take measurements from more sites in the same night, easily available commercial components and software to be reproduced by any interested institution, included amateurs astronomers groups.
Journal of Quantitative Spectroscopy and Radiative Transfer, 2014
In this paper we review new available indicators useful to quantify and monitor light pollution, ... more In this paper we review new available indicators useful to quantify and monitor light pollution, defined as the alteration of the natural quantity of light in the night environment due to introduction of manmade light. With the introduction of recent radiative transfer methods for the computation of light pollution propagation, several new indicators become available. These indicators represent a primary step in light pollution quantification, beyond the bare evaluation of the night sky brightness, which is an observational effect integrated along the line of sight and thus lacking the threedimensional information.
Monthly Notices of the Royal Astronomical Society, 2012
Recent methods to map artificial night sky brightness and stellar visibility across large territo... more Recent methods to map artificial night sky brightness and stellar visibility across large territories or their distribution over the entire sky at any site are based on the computation of the propagation of light pollution with Garstang models, a simplified solution of the radiative transfer problem in the atmosphere which allows a fast computation by reducing it to a ray-tracing approach. They are accurate for a clear atmosphere, when a two-scattering approximation is acceptable, which is the most common situation. We present here up-to-date Extended Garstang Models (EGM) which provide a more general numerical solution for the radiative transfer problem applied to the propagation of light pollution in the atmosphere. We also present the LPTRAN software package, an application of EGM to high-resolution DMSP-OLS satellite measurements of artificial light emissions and to GTOPO30 digital elevation data, which provides an up-to-date method to predict the artificial brightness distribution of the night sky at any site in the World at any visible wavelength for a broad range of atmospheric situations and the artificial radiation density in the atmosphere across the territory. EGM account for (i) multiple scattering, (ii) wavelength from 250 nm to infrared, (iii) Earth curvature and its screening effects, (iv) sites and sources elevation, (v) many kinds of atmosphere with the possibility of custom setup (e.g. including thermal inversion layers), (vi) mix of different boundary layer aerosols and tropospheric aerosols, with the possibility of custom setup, (vii) up to 5 aerosol layers in upper atmosphere including fresh and aged volcanic dust and meteoric dust, (viii) variations of the scattering phase function with elevation, (ix) continuum and line gas absorption from many species, ozone included, (x) up to 5 cloud layers, (xi) wavelength dependant bidirectional reflectance of the ground surface from NASA/MODIS satellites, main models or custom data (snow included), (xii) geographically variable upward light emission function given as a three-parameter function or a Legendre polynomial series. Atmospheric scattering properties or light pollution propagation functions from other sources can be applied too. A more general solution allows to also account for (xiii) mountain screening, (xiv) geographical gradients of atmospheric conditions, including localized clouds, (xv) geographic distribution of ground surfaces, but it suffers from too heavy computational requirements. Comparisons between predictions of classic Garstang models and EGM show close agreement for US62 standard clear atmosphere and typical upward emission function.
LPTRAN/LPDART realistic models, tomography of light pollution, accurate validation methods and ex... more LPTRAN/LPDART realistic models, tomography of light pollution, accurate validation methods and extended satellite data analysis
We extend the method introduced by Cinzano et al. to map the artificial sky brightness in large t... more We extend the method introduced by Cinzano et al. to map the artificial sky brightness in large territories from DMSP satellite data, in order to map the naked-eye star visibility and telescopic limiting magnitudes. For these purposes we take into account the altitude of each land area from GTOPO30 world elevation data, the natural sky brightness in the chosen sky direction, based on Garstang modelling, the eye capability with the naked eye or a telescope, based on the Schaefer and Garstang approach, and the stellar extinction in the visual photometric band. For near-zenith sky directions we also take into account screening by terrain elevation. Maps of naked-eye star visibility and telescopic limiting magnitudes are useful for quantifying the capability of the population to perceive our Universe, evaluating the future evolution, making cross-correlations with statistical parameters, and recognizing areas where astronomical observations or popularization can still acceptably be made. We present, as an application, maps of naked-eye star visibility and total sky brightness in the V band in Europe at the zenith with a resolution of approximately 1 km.
Sky Quality Meter, a low cost and pocket size night sky brightness photometer, opens to the gener... more Sky Quality Meter, a low cost and pocket size night sky brightness photometer, opens to the general public the possibility to quantify the quality of the night sky. Expecting a large diffusion of measurements taken with this instrument, I tested and characterized it. I analyzed with synthetic photometry and laboratory measurements the relationship between the SQM photometrical system and the main systems used in light pollution studies. I evaluated the conversion factors to Johnson’s B and V bands, CIE photopic and CIE scotopic responses for typical spectra and the spectral mismatch correction factors when specific filters are added. Subject headings: light pollution – night sky brightness – photometry – instruments – calibration 1.
ABSTRACT. We obtained the map of the zenith brightness of the night sky in Italy, constructing a ... more ABSTRACT. We obtained the map of the zenith brightness of the night sky in Italy, constructing a simple model. The artificial sky brightness in each site is given by the integration of the contribution produced by each unitary area of surface obtained by applying a propagation function to the upward emission in the area. This operation is a convolution of the upward emission with the propagation function. In fact, the scattering from atmospheric particles and molecules of light emitted upward by the cities spreads the light far from the sources. In pratice, we convolved the DMSP satellite night-time images of the upward light emission in Italy with a propagation function, like the Treanor Law. We used the light emission as measured by DMSP satellite images in order to bypass errors due to differences in the output of cities of the same population arising when using population data to estimate upward flux and in order to take into account also the contribution to the sky brightness p...
ABSTRACT. The direction of the upward light emission has different polluting effects on the sky d... more ABSTRACT. The direction of the upward light emission has different polluting effects on the sky depending on the distance of the observation site. We studied with detailed models for light pollution propagation the ratio bH, at given distances from a city, between the artificial sky luminance bH bL produced by its upward light emission between a given threshold angle θ0 and the vertical and the artificial sky luminance bL produced by its upward light emission between the horizontal and the threshold angle θ0. Our results show that as the distance from the city increases the effects of the emission at high angles above the horizontal decrease relative to the effects of emission at lower angles above the horizontal. Outside some kilometers from cities or towns the light emitted between the horizontal and 10 ◦ is as important as the light emitted at all the other angles in producing the artificial sky luminance. Therefore the protection of a site requires also a careful control of this...
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Papers by Pierantonio Cinzano