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Author Alamús, R.; Bará, S.; Corbera, J.; Escofet, J.; Palà , V.; Pipia, L.; Tardà, A.
Title Ground-based hyperspectral analysis of the urban nightscape Type Journal Article
Year 2017 Publication ISPRS Journal of Photogrammetry and Remote Sensing Abbreviated Journal (up) ISPRS Journal of Photogrammetry and Remote Sensing
Volume 124 Issue Pages 16-26
Keywords Instrumentation; Remote Sensing
Abstract Airborne hyperspectral cameras provide the basic information to estimate the energy wasted skywards by outdoor lighting systems, as well as to locate and identify their sources. However, a complete characterization of the urban light pollution levels also requires evaluating these effects from the city dwellers standpoint, e.g. the energy waste associated to the excessive illuminance on walls and pavements, light trespass, or the luminance distributions causing potential glare, to mention but a few. On the other hand, the spectral irradiance at the entrance of the human eye is the primary input to evaluate the possible health effects associated with the exposure to artificial light at night, according to the more recent models available in the literature. In this work we demonstrate the possibility of using a hyperspectral imager (routinely used in airborne campaigns) to measure the ground-level spectral radiance of the urban nightscape and to retrieve several magnitudes of interest for light pollution studies. We also present the preliminary results from a field campaign carried out in the downtown of Barcelona.
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 0924-2716 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1613
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Author Zheng, Q.; Weng, Q.; Wang, K.
Title Developing a new cross-sensor calibration model for DMSP-OLS and Suomi-NPP VIIRS night-light imageries Type Journal Article
Year 2019 Publication ISPRS Journal of Photogrammetry and Remote Sensing Abbreviated Journal (up) ISPRS Journal of Photogrammetry and Remote Sensing
Volume 153 Issue Pages 36-47
Keywords Remote Sensing; Instrumentation
Abstract Night-time light (NTL) data provides a great opportunity to monitor human activities and settlements. Currently, global-scale NTL data are acquired by two satellite sensors, i.e., DMSP-OLS and VIIRS, but the data collected by the satellites are not compatible. To address this issue, we proposed a method for generating long-term and consistent NTL data. First, a logistic model was employed to estimate and smooth the missing DMSP-OLS data. Second, the Lomb-Scargle Periodogram technique was used to statistically examine the presence of seasonality of monthly VIIRS time series. The seasonal effect, noisy and unstable observations in VIIRS were eliminated by the BFAST time-series decomposition algorithm. Then, we proposed a residuals corrected geographically weighted regression model (GWRc) to generate DMSP-like VIIRS data. A consistent NTL time series from 1996 to 2017 was formed by combining the DMSP-OLS and synthetic DMSP-like VIIRS data. Our assessment shows that the proposed GWRc model outperformed existing methods (e.g., power function model), yielding a lower regression RMSE (6.36), a significantly improved pixel-level NTL intensity consistency (SNDI = 82.73, R2 = 0.986) and provided more coherent results when used for urban area extraction. The proposed method can be used to extend NTL time series, and in conjunction with the upcoming yearly VIIRS data and Black Marble daily VIIRS data, it is possible to support long-term NTL-based studies such as monitoring light pollution in ecosystems, and mapping human activities.
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 0924-2716 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2361
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Author Bierman, A.; Figueiro, M.G.; Rea, M.S.
Title Measuring and predicting eyelid spectral transmittance Type Journal Article
Year 2011 Publication Journal of Biomedical Optics Abbreviated Journal (up) J Biomed Opt
Volume 16 Issue 6 Pages 067011
Keywords Instrumentation; Human Health
Abstract The purpose of the present study was to objectively quantify the spectral transmittance of the eyelid. Reported here are data acquired using a technique that was developed to provide practical and accurate measurements of eyelid transmittance across the visible portion of the electromagnetic spectrum. The empirical data were analyzed in terms of the absorption and scattering characteristics of the constituents of skin to develop a method for predicting eyelid transmission. Results showed that the eyelid has a much higher optical density at short wavelengths than previously published. The mean +/- standard deviation (s.d.) optical density of the eyelid from 450 to 650 nm was 2.1 +/- 0.3 with an optical density range among subjects of approximately 1.0. The study results indicate that skin pigmentation is poorly correlated with eyelid transmission; eyelid transmission is most affected by wavelength-independent macromolecules in the eyelid as well as its overall thickness.
Address Rensselaer Polytechnic Institute, Lighting Research Center, 21 Union Street, Troy, New York 12180, USA
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 1083-3668 ISBN Medium
Area Expedition Conference
Notes PMID:21721832 Approved no
Call Number LoNNe @ kyba @ Serial 1530
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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 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal (up) 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 Chen, H.; Xiong, X.; Geng, X.; Twedt, K.
Title Stray-light correction and prediction for Suomi National Polar-orbiting Partnership visible infrared imaging radiometer suite day-night band Type Journal Article
Year 2019 Publication Journal of Applied Remote Sensing Abbreviated Journal (up) J. Appl. Rem. Sens.
Volume 13 Issue 02 Pages 1
Keywords Instrumentation; Remote Sensing
Abstract The Suomi National Polar-orbiting Partnership visible infrared imaging radiometer suite instrument has successfully operated since its launch in October 2011. Stray-light contamination is much larger than prelaunch expectations, and it causes a major decrease in quality of the day-night band night imagery when the spacecraft is crossing the Northern or Southern day-night terminators. The stray light can be operationally estimated using Earth-view data that are measured over dark surfaces during the new moon each month. More than 7 years of nighttime images have demonstrated that the stray-light contamination mainly depends on the Earth–Sun–spacecraft geometry, so its intensity is generally estimated as a function of the satellite zenith angle. In practice, stray-light contamination is also detector- and scan-angle-dependent. Previous methods of stray-light prediction generally rely on using the known stray light level from the same month in the previous year, when the Earth–Sun–spacecraft geometries had been similar. We propose a new method to predict stray-light contamination. The Kullback–Leibler similarity metric is used as a method to combine data from multiple years with appropriate adjustments for degradation and geometry drifts in order to calculate a fused stray-light contamination correction. The new method provides an improved prediction of stray-light contamination compared to the existing methods and may be considered for future use in the real-time NASA Level-1B products.
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 1931-3195 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2517
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