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Author Wallner, S. url  doi
openurl 
  Title Usage of Vertical Fisheye-Images to Quantify Urban Light Pollution on Small Scales and the Impact of LED Conversion Type Journal Article
  Year 2019 Publication Journal of Imaging Abbreviated Journal J. Imaging  
  Volume 5 Issue 11 Pages 86  
  Keywords Instrumentation  
  Abstract The aim of this work was to develop an easy and quick technique for characterizing various lighting situations, that is, single lamps or illuminated signs and to quantify impacts on small scales like streets, buildings and near areas. The method uses a DSLR-camera equipped with fisheye-lens and the software Sky Quality Camera, both commonly used as part of night sky imagery in the light pollution community, to obtain information about luminance and correlated colour temperature. As a difference to its usual build-up, observed light emitting sources were captured by pointing the camera towards analysed objects, that is, images were taken via vertical plane imaging with very short exposure times under one second. Results have proven that this technique provides a practical way to quantify the lighting efficacy in a certain place or area, as a quantitative analysis of the direct emission towards the observer and the illumination on surroundings, that is, street surfaces, sidewalks and buildings, was performed. When conducting lamp conversions, the method can be used to characterize the gradient of change and could be a useful tool for municipalities to find the optimal lighting solution. The paper shows examples of different lighting situations like single lamps of different types, also containing various luminaires, illuminated billboards or buildings and impacts of the lighting transition to LEDs in the city of Eisenstadt, Austria. The horizontal fisheye method is interdisciplinary applicable, for example, being suitable for lighting management, to sustainability and energy saving purposes.  
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  ISSN 2313-433X ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2749  
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Author Yuan, X.; Jia, L.; Menenti, M.; Zhou, J.; Chen, Q. url  doi
openurl 
  Title Filtering the NPP-VIIRS Nighttime Light Data for Improved Detection of Settlements in Africa Type Journal Article
  Year 2019 Publication Remote Sensing Abbreviated Journal Remote Sensing  
  Volume 11 Issue 24 Pages 3002  
  Keywords Remote Sensing; Instrumentation  
  Abstract Observing and understanding changes in Africa is a hotspot in global ecological environmental research since the early 1970s. As possible causes of environmental degradation, frequent droughts and human activities attracted wide attention. Remote sensing of nighttime light provides an effective way to map human activities and assess their intensity. To identify settlements more effectively, this study focused on nighttime light in the northern Equatorial Africa and Sahel settlements to propose a new method, namely, the patches filtering method (PFM) to identify nighttime lights related to settlements from the National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) monthly nighttime light data by separating signal components induced by biomass burning, thereby generating a new annual image in 2016. The results show that PFM is useful for improving the quality of NPP-VIIRS monthly nighttime light data. Settlement lights were effectively separated from biomass burning lights, in addition to capturing the seasonality of biomass burning. We show that the new 2016 nighttime light image can very effectively identify even small settlements, notwithstanding their fragmentation and unstable power supply. We compared the image with earlier NPP-VIIRS annual nighttime light data from the National Oceanic and Atmospheric Administration (NOAA) National Center for Environmental Information (NCEI) for 2016 and the Sentinel-2 prototype Land Cover 20 m 2016 map of Africa released by the European Space Agency (ESA-S2-AFRICA-LC20). We found that the new annual nighttime light data performed best among the three datasets in capturing settlements, with a high recognition rate of 61.8%, and absolute superiority for settlements of 2.5 square kilometers or less. This shows that the method separates biomass burning signals very effectively, while retaining the relatively stable, although dim, lights of small settlements. The new 2016 annual image demonstrates good performance in identifying human settlements in sparsely populated areas toward a better understanding of human activities.  
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  ISSN 2072-4292 ISBN Medium  
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  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2890  
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Author Bará, S.; Tapia, C.; Zamorano, J. url  doi
openurl 
  Title Absolute Radiometric Calibration of TESS-W and SQM Night Sky Brightness Sensors Type Journal Article
  Year 2019 Publication Sensors Abbreviated Journal Sensors  
  Volume 19 Issue 6 Pages 1336  
  Keywords Instrumentation; calibration; SQM; TESS; photometer; sky brightness  
  Abstract We develop a general optical model and describe the absolute radiometric calibration of the readings provided by two widely-used night sky brightness sensors based on irradiance-to-frequency conversion. The calibration involves the precise determination of the overall spectral sensitivity of the devices and also the constant G relating the output frequency of the light-to-frequency converter chip to the actual band-weighted and field-of-view averaged spectral radiance incident on the detector (brightness). From these parameters, we show how to define a rigorous astronomical absolute photometric system in which the sensor measurements can be reported in units of magnitudes per square arcsecond with precise physical meaning.  
  Address Departmento Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es  
  Corporate Author Thesis  
  Publisher MDPI Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1424-8220 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 2263  
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Author Windle, A. E., Hooley, D. S., & Johnston, D. W. url  doi
openurl 
  Title Robotic Vehicles Enable High-Resolution Light Pollution Sampling of Sea Turtle Nesting Beaches Type Journal Article
  Year 2018 Publication Frontiers in Marine Science Abbreviated Journal  
  Volume 5 Issue 493 Pages  
  Keywords Instrumentation; Animals; Skyglow  
  Abstract Nesting sea turtles appear to avoid brightly lit beaches and often turn back to sea prematurely when exposed to artificial light. Observations and experiments have noted that nesting turtles prefer darker areas where buildings and high dunes act as light barriers. As a result, sea turtles often nest on darker beaches, creating spatial concentrations of nests. Artificial nighttime light, or light pollution, has been quantified using a variety of methods. However, it has proven challenging to make accurate measurements of ambient light at fine scales and on smaller nesting beaches. Additionally, light has traditionally been measured from stationary tripods perpendicular to beach vegetation, disregarding the point of view of a nesting sea turtle. In the present study, nighttime ambient light conditions were assessed on three beaches in central North Carolina: a developed coastline of a barrier island, a nearby State Park on the same barrier island comprised of protected and undeveloped land, and a completely uninhabited wilderness on an adjacent barrier island in the Cape Lookout National Seashore. Using an autonomous terrestrial rover, high resolution light measurements (mag/arcsec2) were collected every minute with two ambient light sensors along transects on each beach. Spatial comparisons between ambient light and nesting density at and between these locations reveal that highest densities of nests occur in regions with lowest light levels, supporting the hypothesis that light pollution from coastal development may influence turtle nesting distribution. These results can be used to support ongoing management strategies to mitigate this pressing conservation issue.  
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  Call Number IDA @ intern @ Serial 2315  
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Author Downey, J.W. url  openurl
  Title Determination of minimum light sense and retinal dark adaptation with presentation of a new type of photometer Type Journal Article
  Year 1919 Publication American Journal of Ophthalmology Abbreviated Journal  
  Volume 2 Issue 1 Pages 13-20  
  Keywords Vision; Instrumentation  
  Abstract This paper reviews the principal hypotheses with reference to light and dark adaptation, and suggests a practical photometer, using a radioactive substance as a standard of comparison. With three illustrations, and experimental findings with this instrument.  
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  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2418  
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