| |
Records |
Links |
|
Author |
Linares, H.; Masana, E.; Ribas, S.J.; Aubé, M.; Simoneau, A.; Bará, S. |
|
| |
Title |
Night sky brightness simulation over Montsec protected area |
Type |
Journal Article |
| |
Year |
2020 |
Publication |
Journal of Quantitative Spectroscopy and Radiative Transfer |
Abbreviated Journal |
Journal of Quantitative Spectroscopy and Radiative Transfer |
|
| |
Volume |
249 |
Issue |
|
Pages |
106990 |
|
| |
Keywords |
Skyglow |
|
| |
Abstract |
Night sky brightness over Montsec Observatory (north-east of Spain) has been computed and checked against measurements using Illumina numerical model [2]. In a previous publication [20] the methodology was validated and light pollution received in the observatory coming from a unique city was computed. Here we present a simulation that includes all the sources that has a significant impact over the quality of the night sky in this area. The decision of which sources should be included in the simulations was taken following the methodology explained by [6]: using a point spread function (PSF) as a simple approach to estimate which sources are brightening the sky dome over the observer. An ad hoc PSF derived with Illumina was used with the purpose of avoiding to have to rely on already existing empirical PSF. The resulting PSF can be used in any location with similar atmospheric conditions. Differences in the spectrum of the lamps can be accounted easily by adjusting a spectrum scale factor. Illumina simulates the artificial sky brightness received (W/sr/m2) by an observer from any direction. Adding the natural sky brightness allows to compare the simulations to measurements taken with different instrumentation. In our case simulations were checked against ASTMON, SQC and SQM measurements. They show a good agreement both in absolute values and in geographical patterns for the three filters studied, B, V and R. The methodology presented opens many possibilities, such as increasing the reliability of the maps that point out the light pollution main contributors for any location, and reducing the amount of time needed to perform an accurate simulation of the night sky brightness. |
|
| |
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 |
GFZ @ kyba @ |
Serial |
2923 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Cinzano, P.; Falchi, F. |
|
| |
Title |
Toward an atlas of the number of visible stars |
Type |
Journal Article |
| |
Year |
2020 |
Publication |
Journal of Quantitative Spectroscopy and Radiative Transfer |
Abbreviated Journal |
Journal of Quantitative Spectroscopy and Radiative Transfer |
|
| |
Volume |
in press |
Issue |
|
Pages |
107059 |
|
| |
Keywords |
Skyglow |
|
| |
Abstract |
Modelling techniques for the propagation of light pollution in the atmosphere allow the computation of maps of artificial night sky brightness in any direction of the sky, involving a large number of details from satellite data. Cinzano et al. (2001a) introduced a method of mapping naked eye star visibility at the zenith from large areas based on satellite radiance measurements and Garstang models of the propagation of light pollution. It takes into account the altitude of each land area from digital elevation data, natural sky brightness in the chosen sky direction based on the Garstang approach, eye capability after Garstang and Schaefer, and atmospheric extinction in the visual photometric band. Here we discuss how to use these methods to obtain maps of the average number of visible stars when looking at the night sky hemisphere, finally answering, site by site, the question of how many stars are visible in the sky. This is not trivial, as the number of stars visible depends on the limiting magnitude in each direction in the sky, and this depends on sky brightness in that direction, atmospheric extinction at that zenith distance and the observer's visual acuity and experience. We present, as an example, a map of the number of visible stars in Italy to an average observer on clear nights with a resolution of approximately 1 km. |
|
| |
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 |
GFZ @ kyba @ |
Serial |
2928 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Barentine, J.C.; Kundracik, F.; Kocifaj, M.; Sanders, J.C.; Esquerdo, G.A.; Dalton, A.M.; Foott, B.; Grauer, A.; Tucker, S.; Kyba, C.C.M. |
|
| |
Title |
Recovering the city street lighting fraction from skyglow measurements in a large-scale municipal dimming experiment |
Type |
Journal Article |
| |
Year |
2020 |
Publication |
Journal of Quantitative Spectroscopy and Radiative Transfer |
Abbreviated Journal |
Journal of Quantitative Spectroscopy and Radiative Transfer |
|
| |
Volume |
253 |
Issue |
|
Pages |
107120 |
|
| |
Keywords |
Skyglow; Remote Sensing |
|
| |
Abstract |
Anthropogenic skyglow dominates views of the natural night sky in most urban settings, and the associated emission of artificial light at night (ALAN) into the environment of cities involves a number of known and suspected negative externalities. One approach to lowering consumption of ALAN in cities is dimming or extinguishing publicly owned outdoor lighting during overnight hours; however, there are few reports in the literature about the efficacy of these programs. Here we report the results of one of the largest municipal lighting dimming experiments to date, involving ~ 20,000 roadway luminaires owned and operated by the City of Tucson, Arizona, U.S. We analyzed both single-channel and spatially resolved ground-based measurements of broadband night sky radiance obtained during the tests, determining that the zenith sky brightness during the tests decreased by ()% near the city center and ()% at an adjacent suburban location on nights when the output of the street lighting system was dimmed from 90% of its full power draw to 30% after local midnight. Modeling these changes with a radiative transfer code yields results suggesting that street lights account for about (14 ± 1)% of light emissions resulting in skyglow seen over the city. A separate derivation from first principles implies that street lighting contributes only % of light seen at the zenith over Tucson. We discuss this inconsistency and suggest routes for future work. |
|
| |
Address |
3223 N 1st Ave, Tucson, AZ 85719; john(at)darksky.org |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Elsevier |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
Enlish |
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 |
GFZ @ kyba @ |
Serial |
2989 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Lamphar, H. |
|
| |
Title |
Spatio-temporal association of light pollution and urban sprawl using remote sensing imagery and GIS: A simple method based in Otsu's algorithm |
Type |
Journal Article |
| |
Year |
2020 |
Publication |
Journal of Quantitative Spectroscopy and Radiative Transfer |
Abbreviated Journal |
Journal of Quantitative Spectroscopy and Radiative Transfer |
|
| |
Volume |
251 |
Issue |
|
Pages |
107060 |
|
| |
Keywords |
Remote Sensing |
|
| |
Abstract |
Automatic thresholding methods are used to detect spatio-temporal changes in the land subject to different natural and anthropogenic processes. Image segmentation plays an important role in this analysis, where urban sprawl detection take place with daylight images. However, recently some investigators have used nocturnal images in remote sensing imagery research. Such georeferenced data represent a good tool for analysis of the light pollution and urban sprawl. There are various physical processes involved in the radiative transfer of the light projected from the cities. Though, with a correct method based on background subtraction, any satellite remotely sensed nocturnal image can be useful in detecting urban sprawl. We base this work on thresholding processes of georeferenced nocturnal satellite images. We used a method combining digital classification techniques, geographic information systems and statistical analyzes. The proposed method is helpful because of a simple implementation and time saving. The pixel intensity of nocturnal images can offer a tool to calculate aspects related to electricity consumption and the efficiency of public lighting. We hope the results motivates other authors to study relationships with other social, natural and economic issues. |
|
| |
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 |
GFZ @ kyba @ |
Serial |
2990 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Kolláth, K.; Kolláth, Z. |
|
| |
Title |
On the feasibility of using ceilometer backscatter profile as input data for skyglow simulation |
Type |
Journal Article |
| |
Year |
2020 |
Publication |
Journal of Quantitative Spectroscopy and Radiative Transfer |
Abbreviated Journal |
Journal of Quantitative Spectroscopy and Radiative Transfer |
|
| |
Volume |
in press |
Issue |
|
Pages |
in press |
|
| |
Keywords |
Skyglow; Instrumentation |
|
| |
Abstract |
Atmospheric conditions can significantly affect the sky brightness originating from artificial lights. Previous works studied the cloudiness, cloud base height, optical depth of cloud, aerosol optical depth and aerosol scale height as atmospheric parameters affecting night sky brightness. Instead of using these parameters as a simplification of the real cloud and aerosol profile, we processed the raw backscatter data of a laser ceilometer instrument. Sky brightness was obtained from camera images available at the same meteorological observation site. Case studies are shown in selected cases, where we analyzed the correspondences with the backscatter data and the camera images. We performed Monte Carlo simulations with the dominant light sources to verify the numerical predictions of sky radiances. Although the limitations of the ceilometer device to obtain optical properties of the atmosphere, ceilometers provide valuable source of data for evaluation of the light pollution measurements. |
|
| |
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 |
GFZ @ kyba @ |
Serial |
2994 |
|
| Permanent link to this record |
