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Author Aceituno, J.; Sánchez, S.F.; Aceituno, F.J.; Galadí-Enríquez, D.; Negro, J.J.; Soriguer, R.C.; Gomez, G.S.
Title (up) An All-Sky Transmission Monitor: ASTMON Type Journal Article
Year 2011 Publication Publications of the Astronomical Society of the Pacific Abbreviated Journal Publications of the Astronomical Society of the Pacific
Volume 123 Issue 907 Pages 1076-1086
Keywords monitoring; light at night; light pollution; skyglow
Abstract We present here the All-Sky Transmission Monitor (ASTMON), designed to perform a continuous monitoring of the surface brightness of the complete night sky in several bands. The data acquired are used to derive, in addition, a subsequent map of the multiband atmospheric extinction at any location in the sky and a map of the cloud coverage. The instrument has been manufactured to withstand extreme weather conditions and to remain operative. Designed to be fully robotic, it is ideal to be installed outdoors as a permanent monitoring station. The preliminary results based on two of the currently operative units (at Doñana National Park, Huelva, and at the Calar Alto Observatory, Almería, Spain) are presented here. The parameters derived using ASTMON are in good agreement with those previously reported, which illustrates the validity of the design and the accuracy of the manufacturing. The information provided by this instrument will be presented in forthcoming articles, once we have accumulated a statistically significant amount of data.
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ISSN 0004-6280 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 195
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Author Kocifaj, M.; Solano Lamphar, H.A.
Title (up) Angular Emission Function of a City and Skyglow Modeling: A Critical Perspective Type Journal Article
Year 2016 Publication Publications of the Astronomical Society of the Pacific Abbreviated Journal Pasp
Volume 128 Issue 970 Pages 124001
Keywords Skyglow
Abstract The radiative transfer equation (RTE) is a common approach to solving the transfer of electromagnetic energy in heterogeneous disperse media, such as atmospheric environment. One-dimensional RTE is a linear boundary value problem that is well suited to plane-parallel atmosphere with no diffuse intensity entering the top of the atmosphere. In nighttime regime, the ground-based light sources illuminate the atmosphere at its bottom interface. However, the light-pollution models conventionally use radiant intensity function rather than radiance. This might potentially result in a number of misconceptions. We focused on similarities and fundamental differences between both functions and clarified distinct consequences for the modeling of skyglow from finite-sized and semi-infinite light-emitting flat surfaces. Minimum requirements to be fulfilled by a City Emission Function (CEF) are formulated to ensure a successful solution of standard and inverse problems. It has been shown that the horizon radiance of a flat surface emitting in accordance with Garstang's function (GEF) would exceed any limit, meaning that the GEF is not an appropriate tool to model skyglow from distant sources. We developed two alternative CEFs to remedy this problem through correction of direct upward emissions; the most important strengths of the modified CEFs are detailed in this paper. Numerical experiments on sky luminance under well-posed and ill-posed boundary conditions were made for two extreme uplight fractions (F) and for three discrete distances from the city edge. The errors induced by replacing radiance with radiant intensity function in the RTE are generally low (15%–30%) if F is as large as 0.15, but alteration of the luminance may range over 1–3 orders of magnitude if F approaches zero. In the latter case, the error margin can increase by a factor of 10–100 or even 1000, even if the angular structure of luminance patterns suffers only weak changes. This is why such a shift in luminance magnitudes can be mistakenly interpreted as the effect of inaccurate estimate of lumens per head of the population rather than the effect of cosine distortion due to ill-posed inputs to the RTE. For that reason, a thorough revision (and/or remediation) of theoretical and computational models is suggested.
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ISSN 0004-6280 ISBN Medium
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Notes Approved no
Call Number LoNNe @ kyba @ Serial 1564
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Author Zhang, J.-C.; Ge, L.; Lu, X.-M.; Cao, Z.-H.; Chen, X.; Mao, Y.-N.; Jiang, X.-J.
Title (up) Astronomical Observing Conditions at Xinglong Observatory from 2007 to 2014 Type Journal Article
Year 2015 Publication Publications of the Astronomical Society of the Pacific Abbreviated Journal Publications of the Astronomical Society of the Pacific
Volume 127 Issue 958 Pages 1292-1306
Keywords Skyglow; light pollution; observatories; China; Xinglong; Sky Quality Meter; SQM
Abstract Xinglong Observatory of the National Astronomical Observatories, Chinese Academy of Sciences (NAOC), is one of the major optical observatories in China, which hosts nine optical telescopes including the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and the 2.16 m reflector. Scientific research from these telescopes is focused on stars, galaxies, and exoplanets using multicolor photometry and spectroscopic observations. Therefore, it is important to provide the observing conditions of the site, in detail, to the astronomers for an efficient use of these facilities. In this article, we present the characterization of observing conditions at Xinglong Observatory based on the monitoring of meteorology, seeing and sky brightness during the period from 2007 to 2014. Meteorological data were collected from a commercial Automatic Weather Station (AWS), calibrated by China Meteorological Administration. Mean and median wind speed are almost constant during the period analyzed and ranged from 1.0 to 3.5 m s-1. However, high wind speed (≥15 m s-1) interrupts observations, mainly, during the winter and spring. Statistical analysis of air temperature showed the temperature difference between daytime and nighttime, which can be solved by opening the ventilation device and the slit of the dome at least 1 hr before observations. Analysis resulted in average percentage of photometric nights and spectroscopic nights are 32% and 63% per year, respectively. The distribution of photometric nights and spectroscopic nights has a significant seasonal tendency, worse in summer due to clouds, dust, and high humidity. Seeing measurements were obtained using the Differential Image Motion Monitor (DIMM). Mean and median values of seeing over 1 year are around 1.9″ and 1.7″, respectively. Eighty percent of nights with seeing values are below 2.6″, whereas the distribution peaks around 1.8″. The measurements of sky brightness are acquired from the Sky Quality Meter (SQM) and photometric observations. Analysis shows that sky brightness at the zenith is around 21.1 mag arcsec-2 and becomes brighter with a larger zenith angle. Sky brightness increases due to the light pollution of the surrounding cities, Beijing, Tangshan, and Chengde. Significant influence toward the direction of Beijing, at an altitude of 30°, can increase the sky brightness up to 20.0 mag arcsec-2. Sky brightness reduces after midnight, mainly because of the influence of city lights and the artificial acts. The above results suggest that Xinglong Observatory is still a good site for astronomical observations. Our analysis of the observing conditions at Xinglong Observatory can be used as a reference to the observers on targets selection, observing strategy, and telescope operation.
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Publisher Royal Astronomical Societynomical Society of the Pacific Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 0004-6280 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1365
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Author Hoag, A.A.
Title (up) City Sky Glow Monitoring at Kitt Peak. Type Journal Article
Year 1973 Publication Publications of the Astronomical Society of the Pacific Abbreviated Journal
Volume 85 Issue 507 Pages 503-507
Keywords Skyglow
Abstract Photographs of night sky have been taken from Kitt Peak on clear moonless nights to provide a record of changes in contamination from artificial lights. Quantitative measures confirm the obvious qualitative impression that city sky-glow brightness is increasing as is the case at most existing observatory sites.
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Call Number LoNNe @ kagoburian @ Serial 565
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Author Aubé, M.; Fortin, N.; Turcotte, S.; García, B.; Mancilla, A.; Maya, J.
Title (up) Evaluation of the Sky Brightness at Two Argentinian Astronomical Sites Type Journal Article
Year 2014 Publication Publications of the Astronomical Society of the Pacific Abbreviated Journal Publications of the Astronomical Society of the Pacific
Volume Issue Pages 000-000
Keywords Skyglow; light pollution; astronomical observatories; sky brightness; site selection; LEO ++; El Leoncito; Kitt Peak; Mont-Mégantic; Argentina
Abstract Light pollution is a growing concern at many levels, especially for the astronomical community. Indeed, not only does artificial lighting veil celestial objects, it disturbs the measurement of many atmospheric phenomena. The sky brightness is one of the most relevant parameters for astronomical site selection. Our goal is to evaluate the sky brightness of two Argentinian observation sites: LEO ++ and El Leoncito. Both sites were preselected to host the Cherenkov Telescope Array. This project consists of an arrangement of many telescopes that can measure high-energy gamma ray emissions via their Cherenkov radiation produced when entering the earth’s atmosphere. In this paper, we describe the measurement methods used to determine whether those sites are valuable or not. We compared our results with the sky radiance of different renowned astronomical sites (Kitt Peak, Arizona, and Mont-Mégantic, Québec, Canada). Among our results, we found that LEO ++ is a good site, however the presence of a low layer of local aerosol can introduce uncertainties in the measurements. Consequently, El Leoncito would be a better option for such an installation. This latter site shows very low sky brightness levels, which are optimal for low light detection.
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Series Editor Series Title Abbreviated Series Title
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ISSN 0004-6280 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1071
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