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Author Bará, S.; Escofet, J.
Title On lamps, walls, and eyes: The spectral radiance field and the evaluation of light pollution indoors Type Journal Article
Year (down) 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal J of Quant Spect and Rad Trans
Volume 205 Issue Pages 267-277
Keywords Instrumentation; Light pollution; Artificial light at night; Light field; Radiance field; Radiometry; Photometry
Abstract Light plays a key role in the regulation of different physiological processes, through several visual and non-visual retinal phototransduction channels whose basic features are being unveiled by recent research. The growing body of evidence on the significance of these effects has sparked a renewed interest in the determination of the light field at the entrance pupil of the eye in indoor spaces. Since photic interactions are strongly wavelength-dependent, a significant effort is being devoted to assess the relative merits of the spectra of the different types of light sources available for use at home and in the workplace. The spectral content of the light reaching the observer eyes in indoor spaces, however, does not depend exclusively on the sources: it is partially modulated by the spectral reflectance of the walls and surrounding surfaces, through the multiple reflections of the light beams along all possible paths from the source to the observer. This modulation can modify significantly the non-visual photic inputs that would be produced by the lamps alone, and opens the way for controlling—to a certain extent—the subject's exposure to different regions of the optical spectrum. In this work we evaluate the expected magnitude of this effect and we show that, for factorizable sources, the spectral modulation can be conveniently described in terms of a set of effective filter-like functions that provide useful insights for lighting design and light pollution assessment. The radiance field also provides a suitable bridge between indoor and outdoor light pollution studies.
Address Área de Óptica, Departamento de Física Aplicada, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language English 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 2163
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Author Zeng, X.; Shao, X.; Qiu, S.; Ma, L.; Gao, C.; Li, C.
Title Stability Monitoring of the VIIRS Day/Night Band over Dome C with a Lunar Irradiance Model and BRDF Correction Type Journal Article
Year (down) 2018 Publication Remote Sensing Abbreviated Journal Remote Sensing
Volume 10 Issue 2 Pages 189
Keywords Instrumentation; Remote Sensing
Abstract The unique feature of the Visible Infrared Imager Radiometer Suite (VIIRS) day/night band (DNB) is its ability to take quantitative measurements of low-light scenes at night. In order to monitor the stability of the high gain stage (HGS) of the DNB, nighttime observations over the Dome C site under moonlight are analyzed in this study. The Miller and Turner 2009 (MT2009) lunar irradiance model has been used to simulate lunar illumination over Dome C. However, the MT2009 model does not differentiate the waxing and waning lunar phases. In this paper, the MT-SWC (SeaWiFS Corrected) lunar irradiance model differentiating the waxing and waning lunar phases is derived by correcting the MT2009 model using lunar observations made by the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS). In addition, a top of atmosphere (TOA) bi-directional reflectance distribution function (BRDF) model during nighttime over Dome C is developed to remove the angular dependence from the nighttime TOA reflectance. The long-term stability monitoring of the DNB high-gain stage (HGS) reveals a lower reflectance factor in 2012 in comparison to the following years, which can be traced back to the change in relative spectral response (RSR) of National Oceanic & Atmospheric Administration’s (NOAA’s) Interface Data Processing Segment (IDPS) VIIRS DNB in April 2013. It also shows the radiometric stability of DNB data, with long-term stability of less than 1.58% over the periods from 2013 to 2016. This method can be used to monitor the radiometric stability of other low-light observing sensors using vicarious calibration sites under moonlight illumination.
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 2072-4292 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1805
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Author Jechow, A.; Ribas, S.J.; Domingo, R.C.; Hölker, F.; Kolláth, Z.; Kyba, C.C.M.
Title Tracking the dynamics of skyglow with differential photometry using a digital camera with fisheye lens Type Journal Article
Year (down) 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 209 Issue Pages 212-223
Keywords Skyglow; Instrumentation
Abstract rtificial skyglow is dynamic due to changing atmospheric conditions and the switching on and off of artificial lights throughout the night. Street lights as well as the ornamental illumination of historical sites and buildings are sometimes switched off at a certain time to save energy. Ornamental lights in particular are often directed upwards, and can therefore have a major contribution towards brightening of the night sky. Here we use differential photometry to investigate the change in night sky brightness and illuminance during an automated regular switch-off of ornamental light in the town of Balaguer and an organized switch-off of all public lights in the village of Àger, both near Montsec Astronomical Park in Spain. The sites were observed during two nights with clear and cloudy conditions using a DSLR camera and a fisheye lens. A time series of images makes it possible to track changes in lighting conditions and sky brightness simultaneously. During the clear night, the ornamental lights in Balaguer contribute over 20% of the skyglow at zenith at the observational site. Furthermore, we are able to track very small changes in the ground illuminance on a cloudy night near Àger.
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 LoNNe @ kyba @ Serial 1807
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Author Ayuga, C.E.T.; Zamorano, J.
Title LICA AstroCalc, a software to analyze the impact of artificial light: Extracting parameters from the spectra of street and indoor lamps Type Journal Article
Year (down) 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 214 Issue Pages 33-38
Keywords Vision; Lighting; Instrumentation
Abstract The night sky spectra of light-polluted areas is the result of the artificial light scattered back from the atmosphere and the reemission of the light after reflections in painted surfaces. This emission comes mainly from street and decorative lamps. We have built an extensive database of lamps spectra covering from UV to near IR and the software needed to analyze them. We describe the LICA-AstroCalc free software that is a user friendly GUI tool to extract information from our database spectra or any other user provided spectrum. The software also includes the complete color database of paints from NCS comprising 1950 types. This helps to evaluate how different colors modify the reflected spectra from different lamps. All spectroscopic measurements have been validated with recommendations from CIELAB and ISO from NCS database.
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 1882
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Author Gaydecki, P.
Title Automated moth flight analysis in the vicinity of artificial light Type Journal Article
Year (down) 2018 Publication Bulletin of Entomological Research Abbreviated Journal Bull Entomol Res
Volume 109 Issue 1 Pages 127-140
Keywords Instrumentation; Animals
Abstract Instrumentation and software for the automated analysis of insect flight trajectories is described, intended for quantifying the behavioural dynamics of moths in the vicinity of artificial light. For its time, this moth imaging system was relatively advanced and revealed hitherto undocumented insights into moth flight behaviour. The illumination source comprised a 125 W mercury vapour light, operating in the visible and near ultraviolet wavelengths, mounted on top of a mobile telescopic mast at heights of 5 and 7.1 m, depending upon the experiment. Moths were imaged in early September, at night and in field conditions, using a ground level video camera with associated optics including a heated steering mirror, wide angle lens and an electronic image intensifier. Moth flight coordinates were recorded at a rate of 50 images per second (fields) and transferred to a computer using a light pen (the only non-automated operation in the processing sequence). Software extracted ground speed vectors and, by instantaneous subtraction of wind speed data supplied by fast-response anemometers, the airspeed vectors. Accumulated density profiles of the track data revealed that moths spend most of their time at a radius of between 40 and 50 cm from the source, and rarely fly directly above it, from close range. Furthermore, the proportion of insects caught by the trap as a proportion of the number influenced by the light (and within the field of view of the camera) was very low; of 1600 individual tracks recorded over five nights, a total of only 12 were caught. Although trap efficiency is strongly dependent on trap height, time of night, season, moonlight and weather, the data analysis confirmed that moths do not exhibit straightforward positive phototaxis. In general, trajectory patterns become more complex with reduced distance from the illumination, with higher recorded values of speeds and angular velocities. However, these characteristics are further qualified by the direction of travel of the insect; the highest accelerations tended to occur when the insect was at close range, but moving away from the source. Rather than manifesting a simple positive phototaxis, the trajectories were suggestive of disorientation. Based on the data and the complex behavioural response, mathematical models were developed that described ideal density distribution in calm air and light wind speed conditions. The models did not offer a physiological hypothesis regarding the behavioural changes, but rather were tools for quantification and prediction. Since the time that the system was developed, instrumentation, computers and software have advanced considerably, allowing much more to be achieved at a small fraction of the original cost. Nevertheless, the analytical tools remain useful for automated trajectory analysis of airborne insects.
Address School of Electrical and Electronic Engineering, University of Manchester,Manchester M13 9PL,UK
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0007-4853 ISBN Medium
Area Expedition Conference
Notes PMID:29745349 Approved no
Call Number GFZ @ kyba @ Serial 1895
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