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Author Hampf, D.; Rowell, G.; Wild, N.; Sudholz, T.; Horns, D.; Tluczykont, M. url  doi
openurl 
  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  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume (down) Series Issue Edition  
  ISSN 0273-1177 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 189  
Permanent link to this record
 

 
Author Falchi, F. url  doi
openurl 
  Title Campaign of sky brightness and extinction measurements using a portable CCD camera: Sky brightness and extinction measurements Type Journal Article
  Year 2011 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal  
  Volume 412 Issue 1 Pages 33-48  
  Keywords sky brightness; monitoring; light pollution; skyglow  
  Abstract In this paper, we present the results of a 12-yr campaign devoted to monitoring the sky brightness affected by different levels of light pollution. Different sites characterized by different altitudes and atmospheric transparency have been considered. The standard photometric Johnson B and V bands were used. An extinction measurement was performed for each site and each night, along with a calibration of the instrument. These measurements have allowed us to build sky brightness maps of the hemisphere above each observing site; each map contains up to 200 data points spread around the sky. We have found a stop in zenith sky brightness growth at the two sites where a time series exists. Using zenith sky brightness measurements taken with and without extensive snow coverage, we weighted the importance of direct versus indirect flux in producing sky glow at several sites.  
  Address  
  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume (down) Series Issue Edition  
  ISSN 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 190  
Permanent link to this record
 

 
Author Femia, N.; Fortunato, M.; Vitelli, M. url  doi
openurl 
  Title Light-to-Light: PV-Fed LED Lighting Systems Type Journal Article
  Year 2013 Publication IEEE Transactions on Power Electronics Abbreviated Journal IEEE Trans. Power Electron.  
  Volume 28 Issue 8 Pages 4063-4073  
  Keywords light-to-light systems; outdoor lighting; lighting technology; LED; LED lighting; photovoltaics; PV  
  Abstract This paper discusses the principle of operation, dynamic modeling, and control design for light-to-light (LtL) systems, whose aim is to directly convert the sun irradiation into artificial light. The system discussed in this paper is composed by a photovoltaic (PV) panel, an LED array, a dc-dc converter dedicated to the maximum power point tracking of the PV panel and a dc-dc converter dedicated to drive the LEDs array. A system controller is also included, whose goal is to ensure the matching between the maximum available PV power and the LED power by means of a low-frequency LEDs dimming. An experimental design example is discussed to illustrate the functionalities of the LtL system.  
  Address Dipt. di Ing. Elettron. e Ing. Inf., Univ. of Salerno, Salerno, Italy  
  Corporate Author Thesis  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume (down) Series Issue Edition  
  ISSN 0885-8993 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 331  
Permanent link to this record
 

 
Author Tähkämö, L.; Ylinen, A.; Puolakka, M.; Halonen, L. url  doi
openurl 
  Title Life cycle cost analysis of three renewed street lighting installations in Finland Type Journal Article
  Year 2012 Publication The International Journal of Life Cycle Assessment Abbreviated Journal Int J Life Cycle Assess  
  Volume 17 Issue 2 Pages 154-164  
  Keywords LED; LED lighting; Life cycle costs; Light-emitting diode; Payback time; Road lighting; Street lighting  
  Abstract Purpose

Outdoor lighting is facing major changes due to the EU legislation on ecodesign of energy-related products, such as the ban of high-pressure mercury (HPM) lamps widely used in outdoor lighting. This article presents life cycle costs (LCC) of three examples of replacing HPM lamps in street lighting in Finland. The purpose of the article is to assess how the development of light-emitting diode (LED) technology affects LCCs and how the division of LCCs differentiates in the cases.

Methods

Two of the cases change from HPM lamps to high-pressure sodium (HPS) lamps. In the third one, HPM lamps are replaced by LED luminaires. LED technology predictions of price and luminous efficacy are included in different scenarios. The calculations consider investment and operating costs and residual value.

Results and discussion

Each replacement reduces the energy costs approximately by half compared to the original HPM lamp luminaires. Energy costs dominate the LCCs of the HPS lamp installations while investment cost is the dominating one in LED luminaire case. The changes from HPM to HPS technology have payback times lower than 9 years, while changing to LED luminaires is not economic. However, the electricity price is low in this case. The payback times of LED installations can be as low as 6 years if the luminaires are installed in 2015 and an average electricity price is used.

Conclusions

The LCCs of real-life case studies cannot be directly compared, since their luminous properties vary. There is a need for a method for including luminous properties in LCC calculations.
 
  Address Lighting Unit, School of Electrical Engineering, Aalto University, P.O. Box 13340, 00076, Aalto, Finland  
  Corporate Author Thesis  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume (down) Series Issue Edition  
  ISSN 0948-3349 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 332  
Permanent link to this record
 

 
Author Rabaza, O.; Galadi-Enriquez, D.; Estrella, A.E.; Dols, F.A. url  doi
openurl 
  Title All-sky brightness monitoring of light pollution with astronomical methods Type Journal Article
  Year 2010 Publication Journal of Environmental Management Abbreviated Journal J Environ Manage  
  Volume 91 Issue 6 Pages 1278-1287  
  Keywords *Astronomy; Calibration; *Environmental Pollutants; *Light  
  Abstract This paper describes a mobile prototype and a protocol to measure light pollution based on astronomical methods. The prototype takes three all-sky images using BVR filters of the Johnson-Cousins astronomical photometric system. The stars are then identified in the images of the Hipparcos and General Catalogue of Photometric Data II astronomical catalogues, and are used as calibration sources. This method permits the measurement of night-sky brightness and facilitates an estimate of which fraction is due to the light up-scattered in the atmosphere by a wide variety of man-made sources. This is achieved by our software, which compares the sky background flux to that of many stars of known brightness. The reduced weight and dimensions of the prototype allow the user to make measurements from virtually any location. This prototype is capable of measuring the sky distribution of light pollution, and also provides an accurate estimate of the background flux at each photometric band.  
  Address Department of Civil Engineering, University of Granada, Severo Ochoa Str. s/n, 18071 Granada, Spain. ovidio@ugr.es  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume (down) Series Issue Edition  
  ISSN 0301-4797 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:20199844 Approved no  
  Call Number IDA @ john @ Serial 192  
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