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Author Li, X.; Levin, N.; Xie, J.; Li, D. url  doi
openurl 
  Title Monitoring hourly night-time light by an unmanned aerial vehicle and its implications to satellite remote sensing Type Journal Article
  Year 2020 Publication (up) Remote Sensing of Environment Abbreviated Journal Remote Sensing of Environment  
  Volume 247 Issue Pages in press  
  Keywords Remote Sensing; Skyglow; Instrumentation  
  Abstract Satellite-observed night-time light in urban areas has been widely used as an indicator for socioeconomic development and light pollution. Up to present, the diurnal dynamics of city light during the night, which are important to understand the nature of human activity and the underlying variables explaining night-time brightness, have hardly been investigated by remote sensing techniques due to limitation of the revisit time and spatial resolution of available satellites. In this study, we employed a consumer-grade unmanned aerial vehicle (UAV) to monitor city light in a study area located in Wuhan City, China, from 8:08 PM, April 15, 2019 to 5:08 AM, April 16, 2019, with an hourly temporal resolution. By using three ground-based Sky Quality Meters (SQMs), we found that the UAV-recorded light brightness was consistent with the ground luminous intensity measured by the SQMs in both the spatial (R2 = 0.72) and temporal dimensions (R2 > 0.94), and that the average city light brightness was consistent with the sky brightness in the temporal dimension (R2 = 0.98), indicating that UAV images can reliably monitor the city's night-time brightness. The temporal analysis showed that different locations had different patterns of temporal changes in their night-time brightness, implying that inter-calibration of two kinds of satellite images with different overpass times would be a challenge. Combining an urban function map of 18 classes and the hourly UAV images, we found that urban functions differed in their temporal light dynamics. For example, the outdoor sports field lost 97.28% of its measured brightness between 8: 08 PM – 4:05 AM, while an administrative building only lost 4.56%, and the entire study area lost 61.86% of its total brightness. Within our study area, the period between 9:06 PM and 10:05 PM was the period with largest amount of light loss. The spectral analysis we conducted showed that city light colors were different in some urban functions, with the major road being the reddest region at 8:08 PM and becoming even redder at 4:05 AM. This preliminary study indicates that UAVs are a good tool to investigate city light at night, and that city light is very complex in both of the temporal and spatial dimensions, requiring comprehensive investigation using more advanced UAV techniques, and emphasizing the need for geostationary platforms for night-time light sensors.  
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  ISSN 0034-4257 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 3014  
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Author Müller, A.; Wuchterl, G.; Sarazin, M. url  openurl
  Title Measuring the Night Sky Brightness with the Lightmeter. Type Journal Article
  Year 2011 Publication (up) ReVMexAA Abbreviated Journal  
  Volume 41 Issue Pages 46–49  
  Keywords Instrumentation; instrumentation: photometers; light pollution; methods: data analysis; methods: observational; site testing  
  Abstract We present a newly developed, low-cost photometer for long-term monitoring of the night sky brightness and

light pollution on Earth. The so-called Lightmeter is an as far as possible stand-alone operational, fully

weatherproof, and maintenance-free device. It provides a high data sampling rate of up to 1 Hz as well as a

superb sensitivity covering the whole brightness range down to the darkest night time conditions. The excellent

performance of the Lightmeter allows a continuously monitoring of the night sky brightness and opens a wide

range of applications at an observatory site like determining overall sky conditions in real time, cloud detection

and estimation of their velocity, measuring relative changes in extinction as well as the detection of long term

trends in brightness caused by an increase of artificial illumination. We will present first results of measurements

taken at Cerro Armazones, one of the best obser
 
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  Notes Approved no  
  Call Number LoNNe @ christopher.kyba @ Serial 471  
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Author Tamir, R.; Lerner, A.; Haspel, C.; Dubinsky, Z.; Iluz, D. url  doi
openurl 
  Title The spectral and spatial distribution of light pollution in the waters of the northern Gulf of Aqaba (Eilat) Type Journal Article
  Year 2017 Publication (up) Scientific Reports Abbreviated Journal Sci Rep  
  Volume 7 Issue Pages 42329  
  Keywords Measurement; Instrumentation; Remote Sensing  
  Abstract The urbanization of the shores of the Gulf of Aqaba has exposed the marine environment there, including unique fringing coral reefs, to strong anthropogenic light sources. Here we present the first in situ measurements of artificial nighttime light under water in such an ecosystem, with irradiance measured in 12 wavelength bands, at 19 measurement stations spread over 44 square km, and at 30 depths down to 30-m depth. At 1-m depth, we find downwelling irradiance values that vary from 4.6 x 10(-4) muW cm(-2) nm(-1) 500 m from the city to 1 x 10(-6) muW cm(-2) nm(-1) in the center of the gulf (9.5 km from the city) in the yellow channel (589-nm wavelength) and from 1.3 x 10(-4) muW cm(-2 )nm(-1) to 4.3 x 10(-5) muW cm(-2) nm(-1) in the blue channel (443-nm wavelength). Down to 10-m depth, we find downwelling irradiance values that vary from 1 x 10(-6) muW cm(-2 )nm(-1) to 4.6 x 10(-4) muW cm(-2) nm(-1) in the yellow channel and from 2.6 x 10(-5) muW cm(-2) nm(-1) to 1.3 x 10(-4) muW cm(-2) nm(-1) in the blue channel, and we even detected a signal at 30-m depth. This irradiance could influence such biological processes as the tuning of circadian clocks, the synchronization of coral spawning, recruitment and competition, vertical migration of demersal plankton, feeding patterns, and prey/predator visual interactions.  
  Address School of Agriculture and Environmental Studies, Beit Berl College, Kfar Saba, Israel  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:28186138; PMCID:PMC5301253 Approved no  
  Call Number GFZ @ kyba @ Serial 1861  
Permanent link to this record
 

 
Author Stone, J.E.; Phillips, A.J.K.; Ftouni, S.; Magee, M.; Howard, M.; Lockley, S.W.; Sletten, T.L.; Anderson, C.; Rajaratnam, S.M.W.; Postnova, S. url  doi
openurl 
  Title Generalizability of A Neural Network Model for Circadian Phase Prediction in Real-World Conditions Type Journal Article
  Year 2019 Publication (up) Scientific Reports Abbreviated Journal Sci Rep  
  Volume 9 Issue 1 Pages 11001  
  Keywords Human Health; Instrumentation  
  Abstract A neural network model was previously developed to predict melatonin rhythms accurately from blue light and skin temperature recordings in individuals on a fixed sleep schedule. This study aimed to test the generalizability of the model to other sleep schedules, including rotating shift work. Ambulatory wrist blue light irradiance and skin temperature data were collected in 16 healthy individuals on fixed and habitual sleep schedules, and 28 rotating shift workers. Artificial neural network models were trained to predict the circadian rhythm of (i) salivary melatonin on a fixed sleep schedule; (ii) urinary aMT6s on both fixed and habitual sleep schedules, including shift workers on a diurnal schedule; and (iii) urinary aMT6s in rotating shift workers on a night shift schedule. To determine predicted circadian phase, center of gravity of the fitted bimodal skewed baseline cosine curve was used for melatonin, and acrophase of the cosine curve for aMT6s. On a fixed sleep schedule, the model predicted melatonin phase to within +/- 1 hour in 67% and +/- 1.5 hours in 100% of participants, with mean absolute error of 41 +/- 32 minutes. On diurnal schedules, including shift workers, the model predicted aMT6s acrophase to within +/- 1 hour in 66% and +/- 2 hours in 87% of participants, with mean absolute error of 63 +/- 67 minutes. On night shift schedules, the model predicted aMT6s acrophase to within +/- 1 hour in 42% and +/- 2 hours in 53% of participants, with mean absolute error of 143 +/- 155 minutes. Prediction accuracy was similar when using either 1 (wrist) or 11 skin temperature sensor inputs. These findings demonstrate that the model can predict circadian timing to within +/- 2 hours for the vast majority of individuals on diurnal schedules, using blue light and a single temperature sensor. However, this approach did not generalize to night shift conditions.  
  Address School of Physics, University of Sydney, Sydney, New South Wales, Australia  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:31358781; PMCID:PMC6662750 Approved no  
  Call Number GFZ @ kyba @ Serial 2667  
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Author Sanchez de Miguel, A.; Kyba, C.C.M.; Zamorano, J.; Gallego, J.; Gaston, K.J. url  doi
openurl 
  Title The nature of the diffuse light near cities detected in nighttime satellite imagery Type Journal Article
  Year 2020 Publication (up) Scientific Reports Abbreviated Journal Sci Rep  
  Volume 10 Issue Pages 7829  
  Keywords Skyglow; Remote Sensing; Instrumentation  
  Abstract Diffuse glow has been observed around brightly lit cities in nighttime satellite imagery since at least the first publication of large scale maps in the late 1990s. In the literature, this has often been assumed to be an error related to the sensor, and referred to as “blooming”, presumably in relation to the effect that can occur when using a CCD to photograph a bright light source. Here we show that the effect seen on the DMSP/OLS, SNPP/VIIRS-DNB and ISS is not only instrumental, but in fact represents a real detection of light scattered by the atmosphere. Data from the Universidad Complutense Madrid sky brightness survey are compared to nighttime imagery from multiple sensors with differing spatial resolutions, and found to be strongly correlated. These results suggest that it should be possible for a future space-based imaging radiometer to monitor changes in the diffuse artificial skyglow of cities.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2909  
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