| Home | << 1 2 3 4 5 6 7 8 9 10 >> [11–20] |
|
| Records | |||||
|---|---|---|---|---|---|
| Author | Kolláth, Z.; Kránicz, B. | ||||
| Title | On the feasibility of inversion methods based on models of urban sky glow | 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 | 27-34 | |
| Keywords | Light pollution; Radiative transfer; Light scattering | ||||
| Abstract | Multi-wavelength imaging luminance photometry of sky glow provides a huge amount of information on light pollution. However, the understanding of the measured data involves the combination of different processes and data of radiation transfer, atmospheric physics and atmospheric constitution. State-of-the-art numerical radiation transfer models provide the possibility to define an inverse problem to obtain information on the emission intensity distribution of a city and perhaps the physical properties of the atmosphere. We provide numerical tests on the solvability and feasibility of such procedures. | ||||
| 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 | 179 | ||
| Permanent link to this record | |||||
| 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. |
||||
| 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 | 180 | ||
| 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 | Sánchez de Miguel, A.; Zamorano, J.; Gómez Castaño, J.; Pascual, S. | ||||
| Title | Evolution of the energy consumed by street lighting in Spain estimated with DMSP-OLS 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 | 109-117 | |
| Keywords | Light pollution; Power consumption; Remote sensing; Light pollution models; Spain | ||||
| Abstract | We present the results of the analysis of satellite imagery to study light pollution in Spain. Both calibrated and non-calibrated DMSP-OLS images were used. We describe the method to scale the non-calibrated DMSP-OLS images which allows us to use differential photometry techniques in order to study the evolution of the light pollution. Population data and DMSP-OLS satellite calibrated images for the year 2006 were compared to test the reliability of official statistics in public lighting consumption. We found a relationship between the population and the energy consumption which is valid for several regions. Finally the true evolution of the electricity consumption for street lighting in Spain from 1992 to 2010 was derived; it has been doubled in the last 18 years in most of the provinces. | ||||
| 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 | 187 | ||
| Permanent link to this record | |||||
| Author | Duriscoe, D.M.; Luginbuhl, C.B.; Moore, C.W. | ||||
| Title | Measuring Night-Sky Brightness with a Wide-Field CCD Camera | Type |
Journal Article | ||
| Year | 2007 | Publication | Publications of the Astronomical Society of the Pacific | Abbreviated Journal | Publ Astron Soc Pac |
| Volume | 119 | Issue | 852 | Pages | 192-213 |
| Keywords | light pollution; light at night; skyglow; monitoring; measurement; CCD | ||||
| Abstract | We describe a system for rapidly measuring the brightness of the night sky using a mosaic of CCD images obtained with a low-cost automated system. The portable system produces millions of independent photometric measurements covering the entire sky, enabling the detailed characterization of natural sky conditions and light domes produced by cities. The measurements are calibrated using images of standard stars contained within the raw data, producing results closely tracking the Johnson V astronomical standard. The National Park Service has collected hundreds of data sets at numerous parks since 2001 and is using these data for the protection and monitoring of the night-sky visual resource. This system also allows comprehensive characterization of sky conditions at astronomical observatories. We explore photometric issues raised by the broadband measurement of the complex and variable night-sky spectrum, and potential indices of night-sky quality. | ||||
| 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 | 0004-6280 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | IDA @ john @ | Serial | 193 | ||
| Permanent link to this record | |||||