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Author Kolláth, Z.; Száz, D.; Tong, K.P.; Kolláth, K.
Title The Colour of the Night Sky Type Journal Article
Year 2020 Publication Journal of Imaging Abbreviated Journal J. Imaging
Volume 6 Issue 9 Pages 90
Keywords Skyglow; Natural light; Instrumentation
Abstract The measurement of night sky quality has become an important task in night sky conservation. Modern measurement techniques involve mainly a calibrated digital camera or a spectroradiometer. However, panchromatic devices are still prevalent to this day, even in the absence of determining the spectral information of the night sky. In the case of multispectral measurements, colour information is currently presented in multiple ways. One of the most frequently used metrics is correlated colour temperature (CCT), which is not without its limitation for the purpose of describing especially the colour of natural night sky. Moreover, visually displaying the colour of the night sky in a quantitatively meaningful way has not attracted sufficient attention in the community of astronomy and light pollution research—most photographs of the night sky are post-processed in a way for aesthetic attractiveness rather than accurate representation of the night sky. The spectrum of the natural night sky varies in a wide range depending on solar activity and atmospheric properties. The most noticeable variation in the visible range is the variation of the atomic emission lines, primarily the green oxygen and orange sodium emission. Based on the accepted models of night sky emission, we created a random spectral database which represents the possible range of night sky radiance distribution. We used this spectral database as a learning set, to create a colour transformation between different colour spaces. The spectral sensitivity of some digital cameras is also used to determine an optimal transformation matrix from camera defined coordinates to real colours. The theoretical predictions were extended with actual spectral measurements in order to test the models and check the local constituents of night sky radiance. Here, we present an extended modelling of night sky colour and recommendations of its consistent measurement, as well as methods of visualising the colour of night sky in a consistent way, namely using the false colour enhancement.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language (up) 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 3120
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Author Strutt, R.J.
Title A photoelectric method of measuring the light of the night sky with studies of the course of variation through the night Type Journal Article
Year 1929 Publication Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character Abbreviated Journal Proc. R. Soc. Lond. A
Volume 124 Issue 794 Pages 395-408
Keywords Instrumentation; Natural Sky Brightness; Airglow
Abstract The investigations already published on the intensity of the night sky have been made by means of visual photometry, using a convenient instrument with a self-contained luminous source of radioactive origin. Nothing could rival this for simplicity and portability; it is always ready and requires no attention. On the other hand visual photometry is not a very satisfactory process even for ordinary light, and with this faint light it is far from giving the desirable degree of accuracy. I have therefore spent much effort in trying to replace it by some photoelectric method of measurement. A satisfactory method has now been evolved, and will be described, together with the results. A preliminary notice of the earlier results was given in a paper written at the request of Prof. S. Chapman, F. R. S., Chairman of the International Committee on Terrestrial and Solar Relationships, the receipt of which was acknowledged by him on June 19, 1928. The relevant passage is:- “Most of the difficulties have been overcome and preliminary observations have been in progress for some months past. I have been able to follow the changes of intensity from hour to hour on clear nights. Some evidence has been found suggesting diurnal periodicity. The observed intensity nearly always increases between nightfall and midnight, beyond which the observations have not usually been carried.”
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Publisher Place of Publication Editor
Language Summary Language (up) Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0950-1207 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 3124
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Author Nievas Rosillo, M.
Title Absolute photometry and Night Sky Brightness with all-sky cameras Type Report
Year 2013 Publication e-prints Complutense Abbreviated Journal e-prints Complutense
Volume Issue 24626 Pages
Keywords Instrumentation; skyglow; measurement; modeling
Abstract All-sky cameras have proven to be powerful tools to continuously monitoring the sky in a wide range of fields in both Astrophysics and Meteorology. In this work, we have developed a complete software pipeline to analyze the night CCD images obtained with one of such systems. This let us to study typical parameters used in Astrophysics to characterize the night sky quality, such as the Sky Brightness, the Cloud Coverage and the Atmospheric Extinction, how they evolve over the time and their variability. Using our software, we analyzed a large set of data from AstMon-OT all-sky camera at Teide Observatory. Results from this work have been applied in the support to the spanish CTA site proposal at Izaña, Tenerife and are being discussed within the CTA consortium. A comparison with data from other devices that have been used in site characterization such as the IAC80 telescope is also presented. This comparison is used to validate the results of the analysis of all-sky images. Finally, we test our software with AstMon-UCM and DSLR cameras. Some general recommendations for the use of DSLR cameras are provided.
Address Departamento de Astrofí­sica y Ciencias de la Atmosfera, Universidad Complutense de Madrid, Madrid, Spain
Corporate Author Thesis Master's thesis
Publisher Place of Publication Madrid Editor
Language English Summary Language (up) English Original Title
Series Editor Series Title e-prints Complutense Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1437
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Author Wahl, F.; Kantermann, T.; Amft, O.
Title How much Light do you get? Estimating Daily Light Exposure using Smartphones Type Conference Article
Year 2014 Publication Proceedings of the 2014 ACM International Symposium on Wearable Computers Abbreviated Journal Proc. of the 2014 ACM International Symposium on Wearable Computers
Volume n/a Issue n/a Pages 43-46
Keywords Instrumentation; light exposure; context inference, light intensity; light intake; circadian clock; circadian rhythm; mobile sensing
Abstract We present an approach to estimate a persons light exposure using smartphones. We used web-sourced weather reports combined with smartphone light sensor data, time of day, and indoor/outdoor information, to estimate illuminance around the user throughout a day. Since light dominates every human’s circadian rhythm and influences the sleep-wake cycle, we developed a smartphone-based system that does not re- quire additional sensors for illuminance estimation. To evaluate our approach, we conducted a free-living study with 12 users, each carrying a smartphone, a head-mounted light reference sensor, and a wrist-worn light sensing device for six consecutive days. Estimated light values were compared to the head-mounted reference, the wrist-worn device and a mean value estimate. Our results show that illuminance could be estimated at less than 20% error for all study participants, outperforming the wrist-worn device. In 9 out of 12 participants the estimation deviated less than 10% from the reference measurements.
Address ACTLab, Chair of Sensor Technology, University of Passau (florian.wahl@uni-passau.de)
Corporate Author Thesis
Publisher ACM Place of Publication Editor
Language English Summary Language (up) English Original Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1206
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Author Cinzano, P.
Title Night Sky Photometry with Sky Quality Meter Type Journal Article
Year 2005 Publication Technical Report 9, ISTIL. V1.4. Abbreviated Journal
Volume Issue Pages
Keywords Instrumentation; light pollution; night sky brightness; photometry; instruments; calibration
Abstract Sky Quality Meter, a low cost and pocket size night sky brightness photometer, opens to the general public the possibility to quantify the quality of the night sky. Expecting a large diffusion of measurements taken with this instrument, I tested and characterized it. I analyzed with synthetic photometry and laboratory measurements the relationship between the SQM photometrical system and the main systems used in light pollution studies. I evaluated the conversion factors to Johnson’s B and V bands, CIE photopic and CIE scotopic responses for typical spectra and the spectral mismatch correction factors when specific filters are added.
Address Dipartimento di Astronomia, Vicolo dell’Osservatorio 2, I-35100 Padova, Italy; cinzano(at)lplab.it
Corporate Author Thesis
Publisher ISTIL Place of Publication Editor
Language English Summary Language (up) 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 LoNNe @ christopher.kyba @ Serial 473
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