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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.
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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
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Author Kolláth, Z.; Cool, A.; Jechow, A.; Kolláth, K.; Száz, D.; Tong, K.P.
Title Introducing the Dark Sky Unit for multi-spectral measurement of the night sky quality with commercial digital cameras 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 107162
Keywords Skyglow; Instrumentation; Measurement; light pollution; Radiometry
Abstract Multi-spectral imaging radiometry of the night sky provides essential information on light pollution (skyglow) and sky quality. However, due to the different spectral sensitivity of the devices used for light pollution measurement, the comparison of different surveys is not always trivial. In addition to the differences between measurement approaches, there is a strong variation in natural sky radiance due to the changes of airglow. Thus, especially at dark locations, the classical measurement methods (such as Sky Quality Meters) fail to provide consistent results. In this paper, we show how to make better use of the multi-spectral capabilities of commercial digital cameras and show their application for airglow analysis. We further recommend a novel sky quality metric the ”Dark Sky Unit”, based on an easily usable and SI traceable unit. This unit is a natural choice for consistent, digital camera-based measurements. We also present our camera system calibration methodology for use with the introduced metrics.
Address ELTE BDPK, Szombathely, Department of Physics, Hungary; zkollath(at)gmail.com
Corporate Author Thesis
Publisher Elsever Place of Publication Elsevier 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 2998
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Author Min, M.; Zheng, J.; Zhang, P.; Hu, X.; Chen, L.; Li, X.; Huang, Y.; Zhu, L.
Title A low-light radiative transfer model for satellite observations of moonlight and earth surface light at night 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 106954
Keywords Remote Sensing; Instrumentation
Abstract Lunar sun-reflected light can be effectively measured through a low-light band or a day/night band (DNB) implemented on space-based optical sensors. Based on moonlight, nocturnal observations for artificial light sources at night can be achieved. However, to date, an open-sourced and mature Low-Light Radiative Transfer Model (LLRTM) for the further understanding of the radiative transfer problem at night is still unavailable. Therefore, this study develops a new LLRTM at night with the correction of the lunar and active surface light sources. First, the radiative transfer equations with an active surface light source are derived for the calculation based on the lunar spectral irradiance (LSI) model. The simulation from this new LLRTM shows a minimal bias when compared with the discrete ordinates radiative transfer (DISORT) model. The simulated results of radiance and reflectance at the top of the atmosphere (TOA) also show that the surface light source has a remarkable impact on the radiative transfer process. In contrast, the change in the lunar phase angle has minimal influence. Also, comparing with space-based DNB radiance observations, LLRTM shows the potential to simulate space-based low-light imager observations under an effective surface light source condition during the night.
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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 2850
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Author Bouroussis, C.A.; Topalis, F.V.
Title Assessment of outdoor lighting installations and their impact on light pollution using unmanned aircraft systems – The concept of the drone-gonio-photometer 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 107155
Keywords Instrumentation; Lighting
Abstract This paper presents the ongoing work of the lighting laboratory to develop a standardized method for the measurement of several types of lighting installations using unmanned aircraft systems. The technology of unmanned aircraft systems can incorporate multiple types of sensors and can be programmed to fly in predefined areas and routes in order to perform complex measurements with limited human intervention. This technology provides the freedom of measurements from several angular positions and altitudes in a fast, easy, accurate and repeatable way. The overall aim of this work is to assess the lighting installations, not only against the applicable lighting standards but also to investigate and reveal issues related to light pollution and obtrusive lighting. The latter are issues that in most cases are neglected due to the lack of standardized methods of calculation and measurement. Current assessment methods require illuminance or luminance measurements of horizontal and vertical surfaces generally from the ground. The proposed approach provides a holistic three-dimensional evaluation of the lighting installations beyond the common methods and geometries and opens the discussion for future update of the relevant standards on outdoor lighting. In the scope of this paper, several proof-of-concept cases are presented.
Address Lighting Laboratory, School of Electrical and Computer Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, 15780, Zografou, Athens, Greece; bouroussis(at)gmail.com
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 GFZ @ kyba @ Serial 2996
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Author Fiorentin, P.; Bertolo, A.; Cavazzani, S.; Ortolani, S.
Title Calibration of digital compact cameras for sky quality measures 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
Keywords Skyglow; Instrumentation
Abstract This work presents the possibility of using the extremely popular compact digital cameras of smartphones or action cameras to perform sky photometry. The newest generation of these devices allows to save raw images. They are not as good as digital single-lens reflex camera, in particular in terms of sensitivity, noise and pixel depth (10 bit versus 12 bit or more), but they have the advantage of being extremely widespread on the population and relatively cheap. These economical digital compact cameras work with an electronic shutter, it overcomes the consumption of mechanics and allows to gather images for long time. The work uses a simple calibration method to transfer raw data from the proprietary RGB color space to the standard CIE 1931 color space. It allows the measurement of sky luminance in cd m−2 with an expected uncertainty of about 20%. Furthermore, the colorimetric calibration allows to know the correlated color temperature of a portion of the sky, it can help the identification of the kind of polluting sources. Aiming at better clarifying the performances of calibrated digital compact cameras, a comparison with a calibrated DSLR camera is presented in outdoor situations showing a good agreement both for luminance and color temperature 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 3063
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