scholarly journals Measurements and Modelling of Aritificial Sky Brightness: Combining Remote Sensing from Satellites and Ground-Based Observations

2021 ◽  
Vol 13 (18) ◽  
pp. 3653
Author(s):  
Zoltán Kolláth ◽  
Dénes Száz ◽  
Kornél Kolláth

In recent decades, considerable research has been carried out both in measuring and modelling the brightness of the sky. Modelling is highly complex, as the properties of light emission (spatial and spectral distribution) are generally unknown, and the physical state of the atmosphere cannot be determined independently. The existing radiation transfer models lack the focus on light pollution and model only a narrow spectral range or do not consider realistic atmospheric circumstances. In this paper, we introduce a new Monte Carlo simulation for modelling light pollution, including the optical density of the atmosphere and multiple photon scattering, then we attempt to combine the available information of satellite and ground-based measurements to check the extent to which it is possible to verify our model. It is demonstrated that we need all the separate pieces of information to interpret the observations adequately.

2019 ◽  
Vol 21 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Emilee Hyde ◽  
Sabine Frank ◽  
John C Barentine ◽  
Helga Kuechly ◽  
Christopher C. M. Kyba

The International Dark-Sky Places (IDSP) program of the International Dark-Sky Association is a voluntary certification in which communities commit via legislative changes to move towards more sustainable lighting that reduces light pollution. As over 115 IDSP have now been certified, it is interesting to ask the extent to which this certification results in reduced light emissions. In this paper, we compared trends in upward light emission of 98 communities located in or near IDSP to those of 98 similarly sized communities further away from the IDSP, using a night lights observing satellite (the Visible Infrared Imaging Radiometer Suite Day-Night Band). The current dataset is not sufficient to distinguish the hypothesis that IDSP certification results in a lower rate of change in upward light emissions from the null hypothesis that IDSP certification has no impact. This result is with regard to upward light emissions only: it is possible that certification has resulted in decreases in night sky brightness that the satellite is not able to observe.


2021 ◽  
Vol 13 (2) ◽  
pp. 258
Author(s):  
Máximo Bustamante-Calabria ◽  
Alejandro Sánchez de Miguel ◽  
Susana Martín-Ruiz ◽  
Jose-Luis Ortiz ◽  
José M. Vílchez ◽  
...  

‘Lockdown’ periods in response to COVID-19 have provided a unique opportunity to study the impacts of economic activity on environmental pollution (e.g., NO2, aerosols, noise, light). The effects on NO2 and aerosols have been very noticeable and readily demonstrated, but that on light pollution has proven challenging to determine. The main reason for this difficulty is that the primary source of nighttime satellite imagery of the earth is the SNPP-VIIRS/DNB instrument, which acquires data late at night after most human nocturnal activity has already occurred and much associated lighting has been turned off. Here, to analyze the effect of lockdown on urban light emissions, we use ground and satellite data for Granada, Spain, during the COVID-19 induced confinement of the city’s population from 14 March until 31 May 2020. We find a clear decrease in light pollution due both to a decrease in light emissions from the city and to a decrease in anthropogenic aerosol content in the atmosphere which resulted in less light being scattered. A clear correlation between the abundance of PM10 particles and sky brightness is observed, such that the more polluted the atmosphere the brighter the urban night sky. An empirical expression is determined that relates PM10 particle abundance and sky brightness at three different wavelength bands.


Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1305
Author(s):  
Feliu Serra-Burriel ◽  
Pedro Delicado ◽  
Fernando M. Cucchietti

In recent years, wildfires have caused havoc across the world, which are especially aggravated in certain regions due to climate change. Remote sensing has become a powerful tool for monitoring fires, as well as for measuring their effects on vegetation over the following years. We aim to explain the dynamics of wildfires’ effects on a vegetation index (previously estimated by causal inference through synthetic controls) from pre-wildfire available information (mainly proceeding from satellites). For this purpose, we use regression models from Functional Data Analysis, where wildfire effects are considered functional responses, depending on elapsed time after each wildfire, while pre-wildfire information acts as scalar covariates. Our main findings show that vegetation recovery after wildfires is a slow process, affected by many pre-wildfire conditions, among which the richness and diversity of vegetation is one of the best predictors for the recovery.


2011 ◽  
Vol 58 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Pedro Rodrigues ◽  
Christoph Aubrecht ◽  
Artur Gil ◽  
Travis Longcore ◽  
Chris Elvidge

Author(s):  
Charles Marseille ◽  
Martin Aubé ◽  
Africa Barreto Velasco ◽  
Alexandre Simoneau

The aerosol optical depth is an important indicator of aerosol particle properties and associated radiative impacts. AOD determination is therefore very important to achieve relevant climate modeling. Most remote sensing techniques to retrieve aerosol optical depth are applicable to daytime given the high level of light available. The night represents half of the time but in such conditions only a few remote sensing techniques are available. Among these techniques, the most reliable are moon photometers and star photometers. In this paper, we attempt to fill gaps in the aerosol detection performed with the aforementioned techniques using night sky brightness measurements during moonless nights with the novel CoSQM: a portable, low cost and open-source multispectral photometer. In this paper, we present an innovative method for estimating the aerosol optical depth by using an empirical relationship between the zenith night sky brightness measured at night with the CoSQM and the aerosol optical depth retrieved at daytime from the AErosol Robotic NETwork. Such a method is especially suited to light-polluted regions with light pollution sources located within a few kilometers of the observation site. A coherent day-to-night aerosol optical depth and Ångström Exponent evolution in a set of 354 days and nights from August 2019 to February 2021 was verified at the location of Santa Cruz de Tenerife on the island of Tenerife, Spain. The preliminary uncertainty of this technique was evaluated using the variance under stable day-to-night conditions, set at 0.02 for aerosol optical depth and 0.75 for Ångström Exponent. These results indicate the set of CoSQM and the proposed methodology appear to be a promising tool to add new information on the aerosol optical properties at night, which could be of key importance to improve climate predictions.


2009 ◽  
Vol 49 (1) ◽  
Author(s):  
A. Barducci ◽  
M. Benvenuti ◽  
F. Castagnoli ◽  
D. Guzzi ◽  
P. Marcoionni ◽  
...  

2020 ◽  
Vol 42 ◽  
pp. 69-81

Light pollution in Slovenia in 2019 with special regard to Natura 2000 areas The article shows the state of light pollution in Slovenia. Remote sensing data from the Suomi satellite were analysed. Light pollution is shown by radiance expressed in nW/(sr cm2 ). In Slovenia, there are large differences in state of light polution. The most polluted areas are located in the area of larger settlements and in areas with higher levels of infrastructure. The spread of light does not stop at the borders of protected areas, so we also analyzed the state of light pollution in Natura 2000 sites in Slovenia. It turns out that the most lightpolluted areas are those that lie around larger settlements or suburbanised regions (Ljubljansko Barje, Šmarna gora, Drava).


2019 ◽  
Vol 17 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Dominika Karpińska ◽  
Mieczysław Kunz

Abstract The paper presents results of research on light pollution in the night sky of Toruń. A permanent network of measuring stations has been established in the city, consisting of 24 sites representing various types of land development and land cover: single-family housing, city centre, multi-family housing, areas overgrown with vegetation and open areas. Within this network, a repeatable direct measurement of the sky brightness using an SQM photometer was carried out over a period of three consecutive months in the summer season, i.e. from June to September 2017. The measurement sessions were conducted in similar weather and astronomical conditions. Based on the obtained data, a spatial distribution of light pollution was determined, ranges of values obtained during the measurements were provided, and the results were additionally referred to the distinguished land cover categories and land development types.


Author(s):  
José A. Vázquez-Mata ◽  
Héctor M. Hernández-Toledo ◽  
Luis A. Martínez-Vázquez ◽  
Atanacio Pani-Cielo

AbstractBeing close to the cities of Puebla to east and Cholula to the north, both having potential for large growth, the National Astronomical Observatory in Tonantzintla (OAN-Tonantzintla) faces the danger of deteriorating its sky conditions even more. In order to maintain competitiveness for education and scientific programs, it is important to preserve the sky brightness conditions. through: 1) our awareness of the night sky characteristics in continuous monitoring campaigns, doing more measurements over the next years to monitor changes and 2) encouraging local authorities about the need to regulate public lighting at the same time, showing them the benefits of such initiatives when well planed and correctly implemented.


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