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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 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 (up) Approved no
Call Number IDA @ john @ Serial 1437
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Author Hampf, D.; Rowell, G.; Wild, N.; Sudholz, T.; Horns, D.; Tluczykont, M.
Title Measurement of night sky brightness in southern Australia Type Journal Article
Year 2011 Publication Advances in Space Research Abbreviated Journal Advances in Space Research
Volume 48 Issue 6 Pages 1017-1025
Keywords Observatories and site testing; Airglow and aurorae; Photometric, polarimetric, and spectroscopic instrumentation
Abstract Night sky brightness is a major source of noise both for Cherenkov telescopes as well as for wide-angle Cherenkov detectors. Therefore, it is important to know the level of night sky brightness at potential sites for future experiments.

The measurements of night sky brightness presented here were carried out at Fowler’s Gap, a research station in New South Wales, Australia, which is a potential site for the proposed TenTen Cherenkov telescope system and the planned wide-angle Cherenkov detector system HiSCORE.

A portable instrument was developed and measurements of the night sky brightness were taken in February and August 2010. Brightness levels were measured for a range of different sky regions and in various spectral bands.

The night sky brightness in the relevant wavelength regime for photomultipliers was found to be at the same level as measured in similar campaigns at the established Cherenkov telescope sites of Khomas, Namibia, and at La Palma. The brightness of dark regions in the sky is about 2 × 1012 photons/(s sr m2) between 300 nm and 650 nm, and up to four times brighter in bright regions of the sky towards the galactic plane. The brightness in V band is 21.6 magnitudes per arcsec2 in the dark regions. All brightness levels are averaged over the field of view of the instrument of about 1.3 × 10−3 sr.

The spectrum of the night sky brightness was found to be dominated by longer wavelengths, which allows to apply filters to separate the night sky brightness from the blue Cherenkov light. The possible gain in the signal to noise ratio was found to be up to 1.2, assuming an ideal low-pass filter.
Address Department of Physics, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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 0273-1177 ISBN Medium
Area Expedition Conference
Notes (up) Approved no
Call Number IDA @ john @ Serial 189
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Author Kyba, C.C.M.; Ruhtz, T.; Fischer, J.; Hölker, F.
Title Red is the new black: how the colour of urban skyglow varies with cloud cover Type Journal Article
Year 2012 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Monthly Notices of the Royal Astronomical Society
Volume 425 Issue 1 Pages 701-708
Keywords Keywords: skyglow; radiative transfer; atmospheric effects; instrumentation: detectors; light pollution
Abstract The development of street lamps based on solid-state lighting technology is likely to introduce a major change in the colour of urban skyglow (one form of light pollution). We demonstrate the need for long-term monitoring of this trend by reviewing the influences it is likely to have on disparate fields. We describe a prototype detector which is able to monitor these changes, and could be produced at a cost low enough to allow extremely widespread use. Using the detector, we observed the differences in skyglow radiance in red, green and blue channels. We find that clouds increase the radiance of red light by a factor of 17.6, which is much larger than that for blue (7.1). We also find that the gradual decrease in sky radiance observed on clear nights in Berlin appears to be most pronounced at longer wavelengths.
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 0035-8711 ISBN Medium
Area Expedition Conference
Notes (up) Approved no
Call Number IDA @ john @ Serial 272
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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 English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes (up) Approved no
Call Number IDA @ john @ Serial 1206
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Author Miller, S.; Straka, W.; Mills, S.; Elvidge, C.; Lee, T.; Solbrig, J.; Walther, A.; Heidinger, A.; Weiss, S.
Title Illuminating the Capabilities of the Suomi National Polar-Orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band Type Journal Article
Year 2013 Publication Remote Sensing Abbreviated Journal Remote Sensing
Volume 5 Issue 12 Pages 6717-6766
Keywords Instrumentation; satellite imagery; nighttime visible/near-infrared; moonlight
Abstract Daytime measurements of reflected sunlight in the visible spectrum have been a staple of Earth-viewing radiometers since the advent of the environmental satellite platform. At night, these same optical-spectrum sensors have traditionally been limited to thermal infrared emission, which contains relatively poor information content for many important weather and climate parameters. These deficiencies have limited our ability to characterize the full diurnal behavior and processes of parameters relevant to improved monitoring, understanding and modeling of weather and climate processes. Visible-spectrum light information does exist during the nighttime hours, originating from a wide variety of sources, but its detection requires specialized technology. Such measurements have existed, in a limited way, on USA Department of Defense satellites, but the Suomi National Polar-orbiting Partnership (NPP) satellite, which carries a new Day/Night Band (DNB) radiometer, offers the first quantitative measurements of nocturnal visible and near-infrared light. Here, we demonstrate the expanded potential for nocturnal low-light visible applications enabled by the DNB. Via a combination of terrestrial and extraterrestrial light sources, such observations are always available—expanding many current existing applications while enabling entirely new capabilities. These novel low-light measurements open doors to a wealth of new interdisciplinary research topics while lighting a pathway toward the optimized design of follow-on satellite based low light visible sensors.
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 2072-4292 ISBN Medium
Area Expedition Conference
Notes (up) Approved no
Call Number LoNNe @ christopher.kyba @ Serial 468
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