On the feasibility of inversion methods based on models of urban sky glow

Kollath, Zoltán; Kránicz, Balázs

doi:10.1016/j.jqsrt.2014.01.008

“…Meanwhile, where some of the key scenarios and observables important for studies of ALAN are not served by these off-the-shelf tools, researchers have developed their own codes. Their approaches range from analytical geometric treatments of radiative transfer, such as Kocifaj [24], to Monte Carlo methods, such as ILLUMINA [25][26][27][28] and the work of Kolláth & Kránicz [29]. However, owing to much of the work around ALAN stemming from astronomy, these tools are often optimized for studies of skyglow, and hence designed for atmospheric radiative transfer.…”

Section: Introductionmentioning

confidence: 99%

Changing streetlighting schemes and the ecological availability of darkness

Morrell,

Hatchell,

Wordingham

et al. 2024

J. R. Soc. Interface.

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Artificial light at night (ALAN), from streetlights and other sources, has a wide variety of impacts on the natural environment. A significant challenge remains, however, to predict at intermediate spatial extents (e.g. across a city) the ALAN that organisms experience under different lighting regimes. Here we use Monte Carlo radiative Transfer to model the three-dimensional lighting environment at, and just above, ground level, on the spatial scales at which animals and humans experience it. We show how this technique can be used to model a suite of both real and hypothetical lighting environments, mimicking the transition of public infrastructure between different lighting technologies. We then demonstrate how the behaviour of animals experiencing these simulated lighting environments can be emulated to probe the availability of darkness, and dark corridors, within them. Our simulations show that no single lighting technology provides an unmitigated alleviation of negative impacts within urban environments, and that holistic treatments of entire lighting environments should be employed when understanding how animals use and traverse them.

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“…The emission function, i.e. the amount of light emitted in different directions is, a priori, unknown for complex situations involving different numbers and types of lighting in urban environments and needs to be calculated through analysis of ground-based scattering observations [1], [2], [3], or by means of theoretical models using either analytic simplifications or more detailed models requiring complex and time consuming high performance computing approaches, e.g. [4], [5], [6], [7].…”

Section: Introductionmentioning

confidence: 99%

Real-World Urban Light Emission Functions and Quantitative Comparison With Spacecraft Measurements

Espey¹,

Yan²,

Patrascu³

2023

Preprint

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We provide quantitative results from GIS-based modelling of urban emission functions for a range of representative low- and mid-rise locations, ranging from individual streets to residential communities within cities as well as entire towns and city regions with the aim of whether lantern photometry or built environment has the dominant effect on light pollution. We demonstrate the scalability of our work by providing results for the largest urban area modelled to date, comprising the central 117 km2 area of Dublin City and containing nearly 42,000 public lights. Our results show a general similarity in the shape of the azimuthally-averaged emission function for all areas examined, with differences in total light output distribution depending primarily on the nature of the lighting and, to a smaller extent, on the obscuring environment including seasonal foliage effects. A comparison with global satellite observations shows that they are consistent with the deduced angular emission function for other low-rise areas worldwide. We further validate our approach by comparing results for a range of urban locations by the close agreement observed in a detailed comparison of with calibrated imagery from the International Space Station. To our knowledge, this is the first such detailed quantitative verification of light loss calculations.

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“…The emission function, i.e., the amount of light emitted in different directions, is, a priori, unknown for complex situations involving different numbers and types of lighting in urban environments comprised of opaque and reflective surfaces. As a result, it needs to be determined via analysis of ground-based scattering observations [1][2][3], or by means of theoretical models using either analytic simplifications or more detailed models requiring complex and time-consuming, high-performance computing approaches, e.g., [4][5][6][7]. As a particular example of a worldwide approach to modelling, Falchi et al developed a globally representative emission function based on their study of zenithal skyglow measurements taken around and outside a sample of urban areas to derive a representative emission function which they then used to predict light pollution at sites remote from the emitting source [8].…”

Section: Introductionmentioning

confidence: 99%

Real-World Urban Light Emission Functions and Quantitative Comparison with Spacecraft Measurements

Espey

¹

,

Yan

²

,

Patrascu

³

2023

Remote Sensing

1

0

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We provide quantitative results from GIS-based modelling of urban emission functions for a range of representative low- and mid-rise locations, ranging from individual streets to residential communities within cities, as well as entire towns and city regions. Our general aim is to determine whether lantern photometry or built environment has the dominant effect on light pollution and whether it is possible to derive a common emission function applicable to regions of similar type. We demonstrate the scalability of our work by providing results for the largest urban area modelled to date, comprising the central 117 km2 area of Dublin City and containing nearly 42,000 public lights. Our results show a general similarity in the shape of the azimuthally averaged emission function for all areas examined, with differences in the angular distribution of total light output depending primarily on the nature of the lighting and, to a smaller extent, on the obscuring environment, including seasonal foliage effects. Our results are also consistent with the emission function derived from the inversion of worldwide skyglow data, supporting our general results by an independent method. Additionally, a comparison with global satellite observations shows that our results are consistent with the deduced angular emission function for other low-rise areas worldwide. Finally, we validate our approach by demonstrating very good agreement between our results and calibrated imagery taken from the International Space Station of a range of residential locations. To our knowledge, this is the first such detailed quantitative verification of light loss calculations and supports the underlying assumptions of the emission function model. Based on our findings, we conclude that it should be possible to apply our approach more generally to produce estimates of the energy and environmental impact of urban areas, which can be applied in a statistical sense. However, more accurate values will depend on the details of the particular locations and require treatment of atmospheric scattering, as well as differences in the spectral nature of the sources.

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On the feasibility of inversion methods based on models of urban sky glow

Cited by 13 publications

References 9 publications

Changing streetlighting schemes and the ecological availability of darkness

Changing streetlighting schemes and the ecological availability of darkness

Real-World Urban Light Emission Functions and Quantitative Comparison With Spacecraft Measurements

Real-World Urban Light Emission Functions and Quantitative Comparison with Spacecraft Measurements

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