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Author Alamús, R.; Bará, S.; Corbera, J.; Escofet, J.; Palà , V.; Pipia, L.; Tardà, A. url  doi
openurl 
  Title Ground-based hyperspectral analysis of the urban nightscape Type Journal Article
  Year 2017 Publication ISPRS Journal of Photogrammetry and Remote Sensing Abbreviated Journal 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  
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  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  
Permanent link to this record
 

 
Author Allik, T.; Ramboyong, L.; Roberts, M.; Walters, M.; Soyka, T.; Dixon, R.; Cho, J. url  doi
openurl 
  Title Enhanced oil spill detection sensors in low-light environments Type Conference Article
  Year 2016 Publication Proc. SPIE 9827, Ocean Sensing and Monitoring VIII, 98270B (May 17, 2016) Abbreviated Journal Proc. SPIE 9827  
  Volume Issue Pages  
  Keywords Instrumentation; Sensors; Cameras; Long wavelength infrared; Short wave infrared radiation; Spectroscopy; Calibration; Remote sensing; Water; Near infrared; Night vision  
  Abstract Although advances have been made in oil spill remote detection, many electro-optic sensors do not provide real-time images, do not work well under degraded visual environments, nor provide a measure of extreme oil thickness in marine environments. A joint program now exists between BSEE and NVESD that addresses these capability gaps in remote sensing of oil spills. Laboratory experiments, calibration techniques, and field tests were performed at Fort Belvoir, Virginia; Santa Barbara, California; and the Ohmsett Test Facility in Leonardo, New Jersey. Weathered crude oils were studied spectroscopically and characterized with LWIR, and low-light-level visible/NIR, and SWIR cameras. We designed and fabricated an oil emulsion thickness calibration cell for spectroscopic analysis and ground truth, field measurements. Digital night vision cameras provided real-time, wide-dynamic-range imagery, and were able to detect and recognize oil from full sun to partial moon light. The LWIR camera provided quantitative oil analysis (identification) for >1 mm thick crude oils both day and night. Two filtered, co-registered, SWIR cameras were used to determine whether oil thickness could be measured in real time. Spectroscopic results revealed that oil emulsions vary with location and weathered state and some oils (e.g., ANS and Santa Barbara seeps) do not show the spectral rich features from archived Deep Water Horizon hyperspectral data. Multi-sensor imagery collected during the 2015 USCG Airborne Oil Spill Remote Sensing and Reporting Exercise and the design of a compact, multiband imager are discussed.  
  Address Active EO Inc.  
  Corporate Author Thesis  
  Publisher SPIE Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 1475  
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Author Ayuga, C.E.T.; Zamorano, J. url  doi
openurl 
  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 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 Bará, S. url  doi
openurl 
  Title Characterizing the zenithal night sky brightness in large territories: how many samples per square kilometre are needed? Type Journal Article
  Year 2017 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal  
  Volume 473 Issue 3 Pages 4164-4173  
  Keywords Instrumentation; atmospheric effects; light pollution; numerical methods; photometry  
  Abstract A recurring question arises when trying to characterize, by means of measurements or theoretical calculations, the zenithal night sky brightness throughout a large territory: how many samples per square kilometre are needed? The optimum sampling distance should allow reconstructing, with sufficient accuracy, the continuous zenithal brightness map across the whole region, whilst at the same time avoiding unnecessary and redundant oversampling. This paper attempts to provide some tentative answers to this issue, using two complementary tools: the luminance structure function and the Nyquist–Shannon spatial sampling theorem. The analysis of several regions of the world, based on the data from the New world atlas of artificial night sky brightness, suggests that, as a rule of thumb, about one measurement per square kilometre could be sufficient for determining the zenithal night sky brightness of artificial origin at any point in a region to within ±0.1 magV arcsec–2 (in the root-mean-square sense) of its true value in the Johnson–Cousins V band. The exact reconstruction of the zenithal night sky brightness maps from samples taken at the Nyquist rate seems to be considerably more demanding.  
  Address 1Departamento de Física Aplicada, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es  
  Corporate Author Thesis  
  Publisher Oxford Academic Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 2164  
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Author Bará, S. url  doi
openurl 
  Title Variations on a classical theme: On the formal relationship between magnitudes per square arcsecond and luminance Type Journal Article
  Year 2017 Publication International Journal of Sustainable Lighting Abbreviated Journal Intl J of Sustainable Lighting  
  Volume 19 Issue 2 Pages 77  
  Keywords Instrumentation; skyglow; luminance; magnitude; sky brigthness; photometry  
  Abstract The formal link between magnitudes per square arcsecond and luminance is discussed in this paper. Directly related to the human visual system, luminance is defined in terms of the spectral radiance of the source, weighted by the CIE V(l) luminous efficiency function, and scaled by the 683 lm/W luminous efficacy constant. In consequence, any exact and spectrum-independent relationship between luminance and magnitudes per square arcsecond requires that the last ones be measured precisely in the CIE V(l) band. The luminance value corresponding to mVC=0 (zero-point of the CIE V(l) magnitude scale) depends on the reference source chosen for the definition of the magnitude system. Using absolute AB magnitudes, the zero point luminance of the CIE V(l) photometric band is 10.96 x 104 cd·m-2.  
  Address Departamento de Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2586-1247 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 2162  
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Author Bará, S.; Escofet, J. url  doi
openurl 
  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 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 Bará, S.; Rigueiro, I.; Lima, R.C. url  doi
openurl 
  Title Monitoring transition: Expected night sky brightness trends in different photometric bands Type Journal Article
  Year 2019 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume 239 Issue Pages 106644  
  Keywords Skyglow; Remote Sensing; Instrumentation  
  Abstract Several light pollution indicators are commonly used to monitor the effects of the transition from outdoor lighting systems based on traditional gas-discharge lamps to solid-state light sources. In this work we analyze a subset of these indicators, including the artificial zenithal night sky brightness in the visual photopic and scotopic bands, the brightness in the specific photometric band of the widely used Sky Quality Meter (SQM), and the top-of-atmosphere radiance detected by the VIIRS-DNB radiometer onboard the satellite Suomi-NPP. Using a single-scattering approximation in a layered atmosphere we quantitatively show that, depending on the transition scenarios, these indicators may show different, even opposite behaviors. This is mainly due to the combined effects of the changes in the sources' spectra and angular radiation patterns, the wavelength-dependent atmospheric propagation processes and the differences in the detector spectral sensitivity bands. It is suggested that the possible presence of this differential behavior should be taken into account when evaluating light pollution indicator datasets for assessing the outcomes of public policy decisions regarding the upgrading of outdoor lighting systems.  
  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 2810  
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Author Bará, S.; Tapia, C.; Zamorano, J. url  doi
openurl 
  Title Absolute Radiometric Calibration of TESS-W and SQM Night Sky Brightness Sensors Type Journal Article
  Year 2019 Publication Sensors Abbreviated Journal Sensors  
  Volume 19 Issue 6 Pages 1336  
  Keywords Instrumentation; calibration; SQM; TESS; photometer; sky brightness  
  Abstract We develop a general optical model and describe the absolute radiometric calibration of the readings provided by two widely-used night sky brightness sensors based on irradiance-to-frequency conversion. The calibration involves the precise determination of the overall spectral sensitivity of the devices and also the constant G relating the output frequency of the light-to-frequency converter chip to the actual band-weighted and field-of-view averaged spectral radiance incident on the detector (brightness). From these parameters, we show how to define a rigorous astronomical absolute photometric system in which the sensor measurements can be reported in units of magnitudes per square arcsecond with precise physical meaning.  
  Address Departmento Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es  
  Corporate Author Thesis  
  Publisher MDPI Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1424-8220 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 2263  
Permanent link to this record
 

 
Author Barentine, J.C. url  doi
openurl 
  Title Methods for Assessment and Monitoring of Light Pollution around Ecologically Sensitive Sites Type Journal Article
  Year 2019 Publication Journal of Imaging Abbreviated Journal J. Imaging  
  Volume 5 Issue 5 Pages 54  
  Keywords Instrumentation; Skyglow; Remote Sensing; Review  
  Abstract Since the introduction of electric lighting over a century ago, and particularly in the decades following the Second World War, indications of artificial light on the nighttime Earth as seen from Earth orbit have increased at a rate exceeding that of world population growth during the same period. Modification of the natural photic environment at night is a clear and imminent consequence of the proliferation of anthropogenic light at night into outdoor spaces, and with this unprecedented change comes a host of known and suspected ecological consequences. In the past two decades, the conservation community has gradually come to view light pollution as a threat requiring the development of best management practices. Establishing those practices demands a means of quantifying the problem, identifying polluting sources, and monitoring the evolution of their impacts through time. The proliferation of solid-state lighting and the changes to source spectral power distribution it has brought relative to legacy lighting technologies add the complication of color to the overall situation. In this paper, I describe the challenge of quantifying light pollution threats to ecologically-sensitive sites in the context of efforts to conserve natural nighttime darkness, assess the current state of the art in detection and imaging technology as applied to this realm, review some recent innovations, and consider future prospects for imaging approaches to provide substantial support for darkness conservation initiatives around the world.  
  Address  
  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2313-433X ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2498  
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Author Bierman, A.; Figueiro, M.G.; Rea, M.S. url  doi
openurl 
  Title Measuring and predicting eyelid spectral transmittance Type Journal Article
  Year 2011 Publication Journal of Biomedical Optics Abbreviated Journal 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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