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Author Bará, S.; Tapia, C.; Zamorano, J.
Title (up) 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 Longcore, T.; Rich, C.; Mineau, P.; MacDonald, B.; Bert, D.G.; Sullivan, L.M.; Mutrie, E.; Gauthreaux, S.A.J.; Avery, M.L.; Crawford, R.L.; Manville, A.M. 2nd; Travis, E.R.; Drake, D.
Title (up) An estimate of avian mortality at communication towers in the United States and Canada Type Journal Article
Year 2012 Publication PloS one Abbreviated Journal PLoS One
Volume 7 Issue 4 Pages e34025
Keywords Ecology; Accidents/*statistics & numerical data; Altitude; Animals; Birds/*injuries; Canada; Computer Communication Networks/*instrumentation; Conservation of Natural Resources/*statistics & numerical data; *Flight, Animal; *Mortality; Regression Analysis; United States
Abstract Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action.
Address The Urban Wildlands Group, Los Angeles, California, United States of America. longcore@urbanwildlands.org
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:22558082; PMCID:PMC3338802 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 475
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Author Li, X.; Ma, R.; Zhang, Q.; Li, D.; Liu, S.; He, T.; Zhao, L.
Title (up) Anisotropic characteristic of artificial light at night – Systematic investigation with VIIRS DNB multi-temporal observations Type Journal Article
Year 2019 Publication Remote Sensing of Environment Abbreviated Journal Remote Sensing of Environment
Volume 233 Issue Pages 111357
Keywords Remote Sensing; Instrumentation
Abstract The released VIIRS DNB nightly images, also known as VIIRS DNB daily nighttime images, provide rich information for time series analysis of global socioeconomic dynamics. Anisotropic characteristic is a possible factor that influences the VIIRS DNB radiance at night and its time series analysis. This study aims to investigate the relationship between viewing angles and VIIRS DNB radiance of Suomi NPP satellite in urban areas. First, twenty-nine points were selected globally to explore the angle variation of Suomi NPP satellite views at night. We found that the variation of the satellite viewing zenith angle (VZA) is consistent (e.g. between 0° and 70°) since the range of VZA is fixed depending on the sensor design, and the range of viewing azimuth angle (VAA) increases with the increase of latitude. Second, thirty points in cities of Beijing, Houston, Los Angeles, Moscow, Quito and Sydney, were used to investigate the angle-radiance relationship. We proposed a zenith-radiance quadratic (ZRQ) model and a zenith-azimuth-radiance binary quadratic (ZARBQ) model to quantify the relationship between satellite viewing angles and artificial light radiance, which has been corrected by removing the moonlight and atmospheric impact from VIIRS DNB radiance products. For all the thirty points, the ZRQ and ZARBQ analysis have averaged R2 of 0.50 and 0.53, respectively, which indicates that the viewing angles are important factors influencing the variation of the artificial light radiance, but extending zenith to zenith-azimuth does not much better explain the variation of the observed artificial light. Importantly, based on the data analysis, we can make the hypothesis that building height may affect the relationship between VZA and artificial light, and cold and hot spot effects are clearly found in tall building areas. These findings are potentially useful to reconstruct more stable time series VIIRS DNB images for socioeconomic applications by removing the angular effects.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0034-4257 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2621
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Author Gaydecki, P.
Title (up) Automated moth flight analysis in the vicinity of artificial light Type Journal Article
Year 2018 Publication Bulletin of Entomological Research Abbreviated Journal Bull Entomol Res
Volume 109 Issue 1 Pages 127-140
Keywords Instrumentation; Animals
Abstract Instrumentation and software for the automated analysis of insect flight trajectories is described, intended for quantifying the behavioural dynamics of moths in the vicinity of artificial light. For its time, this moth imaging system was relatively advanced and revealed hitherto undocumented insights into moth flight behaviour. The illumination source comprised a 125 W mercury vapour light, operating in the visible and near ultraviolet wavelengths, mounted on top of a mobile telescopic mast at heights of 5 and 7.1 m, depending upon the experiment. Moths were imaged in early September, at night and in field conditions, using a ground level video camera with associated optics including a heated steering mirror, wide angle lens and an electronic image intensifier. Moth flight coordinates were recorded at a rate of 50 images per second (fields) and transferred to a computer using a light pen (the only non-automated operation in the processing sequence). Software extracted ground speed vectors and, by instantaneous subtraction of wind speed data supplied by fast-response anemometers, the airspeed vectors. Accumulated density profiles of the track data revealed that moths spend most of their time at a radius of between 40 and 50 cm from the source, and rarely fly directly above it, from close range. Furthermore, the proportion of insects caught by the trap as a proportion of the number influenced by the light (and within the field of view of the camera) was very low; of 1600 individual tracks recorded over five nights, a total of only 12 were caught. Although trap efficiency is strongly dependent on trap height, time of night, season, moonlight and weather, the data analysis confirmed that moths do not exhibit straightforward positive phototaxis. In general, trajectory patterns become more complex with reduced distance from the illumination, with higher recorded values of speeds and angular velocities. However, these characteristics are further qualified by the direction of travel of the insect; the highest accelerations tended to occur when the insect was at close range, but moving away from the source. Rather than manifesting a simple positive phototaxis, the trajectories were suggestive of disorientation. Based on the data and the complex behavioural response, mathematical models were developed that described ideal density distribution in calm air and light wind speed conditions. The models did not offer a physiological hypothesis regarding the behavioural changes, but rather were tools for quantification and prediction. Since the time that the system was developed, instrumentation, computers and software have advanced considerably, allowing much more to be achieved at a small fraction of the original cost. Nevertheless, the analytical tools remain useful for automated trajectory analysis of airborne insects.
Address School of Electrical and Electronic Engineering, University of Manchester,Manchester M13 9PL,UK
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0007-4853 ISBN Medium
Area Expedition Conference
Notes PMID:29745349 Approved no
Call Number GFZ @ kyba @ Serial 1895
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Author Jechow, A.; Kyba, C.; Hölker, F.
Title (up) Beyond All-Sky: Assessing Ecological Light Pollution Using Multi-Spectral Full-Sphere Fisheye Lens Imaging Type Journal Article
Year 2019 Publication Journal of Imaging Abbreviated Journal J. Imaging
Volume 5 Issue 4 Pages 46
Keywords Instrumentation; Skyglow
Abstract Artificial light at night is a novel anthropogenic stressor. The resulting ecological light pollution affects a wide breadth of biological systems on many spatio-temporal scales, from individual organisms to communities and ecosystems. However, a widely-applicable measurement method for nocturnal light providing spatially resolved full-spectrum radiance over the full solid angle is still missing. Here, we explain the first step to fill this gap, by using a commercial digital camera with a fisheye lens to acquire vertical plane multi-spectral (RGB) images covering the full solid angle. We explain the technical and practical procedure and software to process luminance and correlated color temperature maps and derive illuminance. We discuss advantages and limitations and present data from different night-time lighting situations. The method provides a comprehensive way to characterize nocturnal light in the context of ecological light pollution. It is affordable, fast, mobile, robust, and widely-applicable by non-experts for field work.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2313-433X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2327
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