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Author Bará, S.
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 (up) 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.; Tapia, C.; Zamorano, J.
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 (up) 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
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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 J Biomed Opt
Volume 16 Issue 6 Pages 067011
Keywords (up) 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 Voigt, L.P.; Reynolds, K.; Mehryar, M.; Chan, W.S.; Kostelecky, N.; Pastores, S.M.; Halpern, N.A.
Title Monitoring sound and light continuously in an intensive care unit patient room: A pilot study Type Journal Article
Year 2016 Publication Journal of Critical Care Abbreviated Journal Journal of Critical Care
Volume 38 Issue 21 Pages 5952-5961
Keywords (up) Instrumentation; Human Health
Abstract Purpose

To determine the feasibility of continuous recording of sound and light in the intensive care unit (ICU).

Materials and Methods

Four one-hour baseline scenarios in an empty ICU patient room by day and night (doors open or closed and maximal or minimal lighting) and two daytime scenarios simulating a stable and unstable patient (quiet or loud devices and staff) were conducted. Sound and light levels were continuously recorded using a commercially available multisensor monitor and transmitted via the hospital's network to a cloud-based data storage and management system.

Results

The empty ICU room was loud with similar mean sound levels for the day and night simulations of 45–46 dBA. Mean levels for maximal lighting during day and night ranged from 1306–1812 lux and mean levels for minimum lighting were 1–3 lux. The mean sound levels for the stable and unstable patient simulations were 61 and 81 dBA, respectively. The mean light levels were 349 lux for the stable patient and 1947 lux for the unstable patient.

Conclusions

Combined sound and light can be continuously and easily monitored in the ICU setting. Incorporating sound and light monitors in ICU rooms may promote an enhanced patient and staff centered healing environment.
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 0883-9441 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1614
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Author Jung, B.; Inanici, M.
Title Measuring circadian lighting through high dynamic range photography Type Journal Article
Year 2018 Publication Lighting Research & Technology Abbreviated Journal Lighting Research & Technology
Volume in press Issue Pages in press
Keywords (up) Instrumentation; Human Health
Abstract The human ocular system functions in a dual manner. While the most well-known function is to facilitate vision, a growing body of research demonstrates its role in resetting the internal body clock to synchronize with the 24-hour daily cycle. Most research on circadian rhythms is performed in controlled laboratory environments. Little is known about the variability of circadian light within the built and natural environments. Currently, very few specialized devices measure the circadian light, and they are not accessible to many researchers and practitioners. In this paper, tristimulus colour calibration procedures for high dynamic range photography are developed to measure circadian lighting. Camera colour accuracy is evaluated through CIE trichromatic (XYZ) measurements; and the results demonstrate a strong linear relationship between the camera recordings and a scientific-grade colorimeter. Therefore, it is possible to correct for the colour aberrations and use high dynamic range photographs to measure both photopic and circadian lighting values. Spectrophotometric measurements are collected to validate the methodology. Results demonstrate that measurements from high dynamic range photographs can correspond to the physical quantity of circadian luminance with reasonable precision and repeatability. Circadian data collected in built environments can be utilized to study the impact of design decisions on human circadian entrainment and to create guidelines and metrics for designing circadian friendly environments.
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 1477-1535 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1979
Permanent link to this record