Aboushelib, M. F., Abozaid, A. A., Nawar, S., Hendy, Y. H. M., & Morcos, A. B. (2019). Preliminary site selection for an observatory in the Egyptian Eastern Desert. Astrophys Space Sci, 364(10), 163.
Abstract: This work aims for choosing preliminary sites that can be candidates for a new astronomical observatory that will replace the Kottamia observatory. The candidate sites have been selected to be investigated after proposing a few criteria. Concerning light pollution and elevation of the sites as the main factors, we chose the candidate sites depending on the zenith sky brightness and the elevation. The night sky brightness has been measured using a Sky Quality Meter at different altitude degrees and the values of the zenith sky brightness were compared to those of different observatory sites. Our night sky brightness observations were found to be in agreement with the satellite’s data and comparable to those of dark sites, with average values of 22.07, 22.03, 21.57 and 21.58 magSQM/arcsec2. We also have obtained the Aerosol Optical Depth (AOD) and extinction coefficient due to the aerosol for the candidate sites using satellite data (Terra/MODIS).
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Aubé, M., & Roby, J. (2014). Sky brightness levels before and after the creation of the first International Dark Sky Reserve, Mont-Mégantic Observatory, Québec, Canada. JQSRT, 139, 52–63.
Abstract: In 2007, the area around the Mont-Mégantic Observatory (MMO) was officially certified by the International Dark-Sky Association and the Royal Astronomy Association of Canada as the first International Dark Sky Reserve (IDSR). In order to be able to investigate the impact of Artificial Light at Night on night sky brightness before and after the establishment of the IDSR, we used a heterogeneous artificial sky brightness model including an implicit calculation of 2nd order scattering (ILLUMINA) developed by Martin Aubé's group. This model generates three kinds of outputs: the sky radiance at the given site, observing angle and wavelength and the corresponding contribution and sensitivity maps. The maps allow for the identification of the origin of the sky radiance according to each part of the surrounding territory. For summer clear sky conditions, the results show that replacing light fixtures within a 25 km radius around the MMO with cut-off High Pressure Sodium devices and reducing the total installed radiant power to ~40% of its initial level are very efficient ways of reducing artificial sky brightness. The artificial sky brightness reduction at zenith observed after the establishment of the IDSR was ~50% in the 546 nm mercury spectral line, while the reduction obtained in the 569 nm sodium line was ~30%. A large part of that reduction can be associated to the reduction in radiant power. The contribution and sensitivity maps highlight critical zones where any changes in the lighting infrastructure have the most important impact on sky brightness at the MMO. Contribution and sensitivity maps have been used to analyze the detailed origin of sky brightness reduction. The results of this study are intended to support authorities in the management of their lighting infrastructure with the goal of reducing sky brightness. The results have been shared with MMO officials and are being used as a tool to improve sky quality at the observatory.
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den Outer, P., Lolkema, D., Haaima, M., van der Hoff, R., Spoelstra, H., & Schmidt, W. (2011). Intercomparisons of nine sky brightness detectors. Sensors (Basel), 11(10), 9603–9612.
Abstract: Nine Sky Quality Meters (SQMs) have been intercompared during a night time measurement campaign held in the Netherlands in April 2011. Since then the nine SQMs have been distributed across The Netherlands and form the Dutch network for monitoring night sky brightness. The goal of the intercomparison was to infer mutual calibration factors and obtain insight into the variability of the SQMs under different meteorological situations. An ensemble average is built from the individual measurements and used as a reference to infer the mutual calibration factors. Data required additional synchronization prior to the calibration determination, because the effect of moving clouds combined with small misalignments emerges as time jitter in the measurements. Initial scatter of the individual instruments lies between +/-14%. Individual night time sums range from -16% to +20%. Intercalibration reduces this to 0.5%, and -7% to +9%, respectively. During the campaign the smallest luminance measured was 0.657 +/- 0.003 mcd/m(2) on 12 April, and the largest value was 5.94 +/- 0.03 mcd/m(2) on 2 April. During both occurrences interfering circumstances like snow cover or moonlight were absent.
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Longcore, T., Duriscoe, D., Aubé, M., Jechow, A., Kyba, C. C. M., & Pendoley, K. L. (2020). Commentary: Brightness of the Night Sky Affects Loggerhead (Caretta caretta) Sea Turtle Hatchling Misorientation but Not Nest Site Selection. Front. Mar. Sci., 7.
Abstract: A Commentary on “Brightness of the Night Sky Affects Loggerhead (Caretta caretta) Sea Turtle Hatchling Misorientation but Not Nest Site Selection” by Stanley, T. R., White, J. M., Teel, S., and Nicholas, M. (2020). Front. Mar. Sci. 7:221. doi: 10.3389/fmars.2020.00221
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Posudin, Y. (2014). Measurement of Light Pollution. In Methods of Measuring Environmental Parameters (Vol. Chapter 33). John Wiley & Sons, Inc.
Abstract: Digital photography is based on the conversion of light by sensitive matrix (array of electronic photodetectors) to capture the image which is then digitized and stored as a computer file for further processing and printing. The spectral sensitivity of the cameras is in good agreement with the spectrum of action of the photosensitive hormone melatonin. Digital photography can be used to quantify light pollution acting on the physiology of living organisms. The chapter discusses the principles of spectrophotometry. A portable spectrophotometer for the measurement of light pollution is proposed by Cinzano. It consists of a cooled CCD camera and a small spectrographic head which is equipped with a De Amici prism composed of two external crown prisms and an inner Flint prism. Sky quality meter (SQM) is a portable photometer for measuring sky brightness and for light pollution monitoring. This device collects the light from a wide solid angle.
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