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| Author | Kocifaj, M. | ||||
| Title | Modeling the night-sky radiances and inversion of multi-angle and multi-spectral radiance data | Type | Journal Article | ||
| Year | 2014 | Publication | Journal of Quantitative Spectroscopy and Radiative Transfer | Abbreviated Journal | Journal of Quantitative Spectroscopy and Radiative Transfer |
| Volume | 139 | Issue | Pages | 35-42 | |
| Keywords | Sky-glow; Light pollution; Aerosols; Light scattering; Inverse problems | ||||
| Abstract | Information on a city's emission pattern is crucial for any reasonable predictions of night sky radiances. Unfortunately, the bulk radiant intensity distribution as a function of zenith angle is scarcely available for any city throughout the world. Even if the spatial arrangements of urban light fixtures and lamp specifications are known, the cumulative effect on upwardly directed beams is difficult to determine; due to heterogeneity of the ambient environment, reflectance from ground surfaces, arbitrarily scattered obstacles, orography of terrain and many other site specific factors. The present paper develops a theoretical model and a numerical technique applicable to the retrieval of a City Emission Function (CEF) from the spectral sky radiances measured under clear sky conditions. Mathematically it is an inverse problem that is solved using a regularization algorithm in which the minimization routines penalize non-smooth solutions and the radiant intensity pattern is found subject to regularizing constraints. When spectral sky radiances are measured at a set of discrete wavelengths or at a set of discrete distances from the monitored light source, both the aerosol optical properties and the CEF can be determined concurrently. One great advantage of this approach is that no a-priori assumptions need to be made concerning aerosol properties, such as aerosol optical depth. The numerical experiment on synthetically generated city emissions' patterns has proven the functionality of the method presented. |
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| Address | ICA, Slovak Academy of Sciences, Dúbravská Road 9, 845 03 Bratislava, Slovakia. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-4073 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
Notes  |
Approved | no | |||
| Call Number | IDA @ john @ | Serial | 180 | ||
| Permanent link to this record | |||||
| Author | Kocifaj, M. | ||||
| Title | Night sky luminance under clear sky conditions: Theory vs. experiment | Type | Journal Article | ||
| Year | 2014 | Publication | Journal of Quantitative Spectroscopy and Radiative Transfer | Abbreviated Journal | Journal of Quantitative Spectroscopy and Radiative Transfer |
| Volume | 139 | Issue | Pages | 43-51 | |
| Keywords | Sky glow; Luminance; Luminaire; City emission function; Anthropogenic; Single scattering; Inverse problems | ||||
| Abstract | Sky glow is caused by both natural phenomena and factors of anthropogenic origin, and of the latter ground-based light sources are the most important contributors for they emit the spatially linked spectral radiant intensity distribution of artificial light sources, which are further modulated by local atmospheric optics and perceived as the diffuse light of a night sky. In other words, sky glow is closely related to a city's shape and pattern of luminaire distribution, in practical effect an almost arbitrary deployment of random orientation of heterogeneous electrical light sources. Thus the luminance gradation function measured in a suburban zone or near the edges of a city is linked to the City Pattern or vice versa. It is shown that clear sky luminance/radiance data recorded in an urban area can be used to retrieve the bulk luminous/radiant intensity distribution if some a-priori information on atmospheric aerosols is available. For instance, the single scattering albedo of aerosol particles is required under low turbidity conditions, as demonstrated on a targeted experiment in the city of Frýdek-Mistek. One of the main advantages of the retrieval method presented in this paper is that the single scattering approximation is satisfactorily accurate in characterizing the light field near the ground because the dominant contribution to the sky glow has originated from beams propagated along short optical paths. |
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| Address | ICA, Slovak Academy of Sciences, Dúbravská Road 9, 845 03 Bratislava, Slovakia | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-4073 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes |
Approved | no | |||
| Call Number | IDA @ john @ | Serial | 181 | ||
| Permanent link to this record | |||||
| Author | Kolláth, Z. | ||||
| Title | Measuring and modelling light pollution at the Zselic Starry Sky Park | Type | Journal Article | ||
| Year | 2010 | Publication | Journal of Physics: Conference Series | Abbreviated Journal | J. Phys.: Conf. Ser. |
| Volume | 218 | Issue | Pages | 012001 | |
| Keywords | Skyglow; modeling; measurement; SQM; sky brightness; Zselic; International Dark Sky Park; Hungry; measurements; modeling; light pollution; skyglow; radiative transfer | ||||
| Abstract | One of the first 'International Dark-sky Parks' in Europe was established at the Zselic Landscape Protection Area in Hungary. A special monitoring program has been carrying on to survey the quality of the night sky using 'Sky Quality Meters' and DSLR cameras. The main conclusion of our measurements is that the local villages have only a minimal effect on the quality of the sky. There are light-domes due to the neighbouring cities only close to the horizon, the main source of obtrusive light is the city of Kaposvár. The anthropogenic component of zenith luminance of the night sky is obtained as the function of the distance from the city centre of Kaposvár. Our data were modelled by radiation transfer calculations. These results can help to draw attention to the energy emitted useless to the space and to protect our nocturnal landscape of nature parks for the next generations. | ||||
| Address | Konkoly Observatory, Konkoly Thege u. 15-17, H-1121 Budapest, Hungary; kollath(at)konkoly.hu | ||||
| Corporate Author | Thesis | ||||
| Publisher | IOP | Place of Publication | Editor | ||
| Language | English | Summary Language | English | Original Title | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1742-6596 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes |
Approved | no | |||
| Call Number | IDA @ john @ | Serial | 1436 | ||
| Permanent link to this record | |||||
| Author | Nievas Rosillo, M. | ||||
| Title | Absolute photometry and Night Sky Brightness with all-sky cameras | Type | Report | ||
| Year | 2013 | Publication | e-prints Complutense | Abbreviated Journal | e-prints Complutense |
| Volume | Issue | 24626 | Pages | ||
| Keywords | Instrumentation; skyglow; measurement; modeling | ||||
| Abstract | All-sky cameras have proven to be powerful tools to continuously monitoring the sky in a wide range of fields in both Astrophysics and Meteorology. In this work, we have developed a complete software pipeline to analyze the night CCD images obtained with one of such systems. This let us to study typical parameters used in Astrophysics to characterize the night sky quality, such as the Sky Brightness, the Cloud Coverage and the Atmospheric Extinction, how they evolve over the time and their variability. Using our software, we analyzed a large set of data from AstMon-OT all-sky camera at Teide Observatory. Results from this work have been applied in the support to the spanish CTA site proposal at Izaña, Tenerife and are being discussed within the CTA consortium. A comparison with data from other devices that have been used in site characterization such as the IAC80 telescope is also presented. This comparison is used to validate the results of the analysis of all-sky images. Finally, we test our software with AstMon-UCM and DSLR cameras. Some general recommendations for the use of DSLR cameras are provided. | ||||
| Address | Departamento de Astrofísica y Ciencias de la Atmosfera, Universidad Complutense de Madrid, Madrid, Spain | ||||
| Corporate Author | Thesis | Master's thesis | |||
| Publisher | Place of Publication | Madrid | Editor | ||
| Language | English | Summary Language | English | Original Title | |
| Series Editor | Series Title | e-prints Complutense | Abbreviated Series Title | ||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Medium | |||
| Area | Expedition | Conference | |||
| Notes |
Approved | no | |||
| Call Number | IDA @ john @ | Serial | 1437 | ||
| Permanent link to this record | |||||
| Author | Puschnig, J.; Posch, T.; Uttenthaler, S. | ||||
| Title | Night sky photometry and spectroscopy performed at the Vienna University Observatory | Type | Journal Article | ||
| Year | 2014 | Publication | Journal of Quantitative Spectroscopy and Radiative Transfer | Abbreviated Journal | Journal of Quantitative Spectroscopy and Radiative Transfer |
| Volume | 139 | Issue | Pages | 64-75 | |
| Keywords | Atmospheric effects; Site testing; Light pollution; Techniques: photometric; Techniques: spectroscopic | ||||
| Abstract | We present night sky brightness measurements performed at the Vienna University Observatory and at the Leopold-Figl-Observatorium für Astrophysik, which is located about 35 km to the southwest of Vienna. The measurements have been performed with Sky Quality Meters made by Unihedron. They cover a time span of roughly one year and have been carried out every night, yielding a luminance value every 7 s and thus delivering a large amount of data. In this paper, the level of skyglow in Vienna, which ranges from 15 to 19.25 magSQM arcsec−2 is presented for the very first time in a systematic way. We discuss the influence of different environmental conditions on the night sky brightness and implications for human vision. We show that the circalunar rhythm of night sky brightness is almost extinguished at our observatory due to light pollution. Additionally, we present spectra of the night sky in Vienna, taken with a 0.8 m telescope. The goal of these spectroscopic measurements was to identify the main types of light sources and the spectral lines which cause the skyglow in Vienna. It turned out that fluorescent lamps are responsible for the strongest lines of the night sky above Vienna (e.g. lines at 546 nm and at 611 nm). |
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| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-4073 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes |
Approved | no | |||
| Call Number | IDA @ john @ | Serial | 183 | ||
| Permanent link to this record | |||||