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Author Bará, S.
Title Variations on a classical theme: On the formal relationship between magnitudes per square arcsecond and luminance Type Journal Article
Year 2017 Publication International Journal of Sustainable Lighting Abbreviated Journal Intl J of Sustainable Lighting
Volume 19 Issue 2 Pages 77
Keywords Instrumentation; skyglow; luminance; magnitude; sky brigthness; photometry
Abstract The formal link between magnitudes per square arcsecond and luminance is discussed in this paper. Directly related to the human visual system, luminance is defined in terms of the spectral radiance of the source, weighted by the CIE V(l) luminous efficiency function, and scaled by the 683 lm/W luminous efficacy constant. In consequence, any exact and spectrum-independent relationship between luminance and magnitudes per square arcsecond requires that the last ones be measured precisely in the CIE V(l) band. The luminance value corresponding to mVC=0 (zero-point of the CIE V(l) magnitude scale) depends on the reference source chosen for the definition of the magnitude system. Using absolute AB magnitudes, the zero point luminance of the CIE V(l) photometric band is 10.96 x 104 cd·m-2.
Address Departamento de Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 2586-1247 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2162
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Author Tauc, M.J.; Fristrup, K.M.; Repasky, K.S.; Shaw, J.A.
Title Field demonstration of a wing-beat modulation lidar for the 3D mapping of flying insects Type Journal Article
Year 2019 Publication OSA Continuum Abbreviated Journal OSA Continuum
Volume 2 Issue 2 Pages 332
Keywords Instrumentation; Animals
Abstract We describe a wing-beat modulation lidar system designed for the 3D mapping of flying insects in ecological or entomological studies. To better understand the signals from this instrument, we analyzed simulated signals to identify how they were affected by various imperfections, such as variations in the spacing and amplitude of each individual wing-beat reflection. In addition, a radiometric model was used to estimate signal-to-noise ratio to gain insight into the relationships between the optical system design and insect parameters (e.g., wing size, reflectivity, or diffusivity).
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 2578-7519 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2209
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Author Mills, S.; Miller, S.
Title VIIRS Day/Night Band--Correcting Striping and Nonuniformity over a Very Large Dynamic Range Type Journal Article
Year 2016 Publication Journal of Imaging Abbreviated Journal J. Imaging
Volume 2 Issue 1 Pages 9
Keywords Instrumentation
Abstract The Suomi National Polar-orbiting (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Day-Night Band (DNB) measures visible and near-infrared light extending over seven orders of magnitude of dynamic range. This makes radiometric calibration difficult. We have observed that DNB imagery has striping, banding and other nonuniformities—day or night. We identified the causes as stray light, nonlinearity, detector crosstalk, hysteresis and mirror-side variation. We found that these affect both Earth-view and calibration signals. These present an obstacle to interpretation by users of DNB products. Because of the nonlinearity we chose the histogram matching destriping technique which we found is successful for daytime, twilight and nighttime scenes. Because of the very large dynamic range of the DNB, we needed to add special processes to the histogram matching to destripe all scenes, especially imagery in the twilight regions where scene illumination changes rapidly over short distances. We show that destriping aids image analysts, and makes it possible for advanced automated cloud typing algorithms. Manual or automatic identification of other features, including polar ice and gravity waves in the upper atmosphere are also discussed. In consideration of the large volume of data produced 24 h a day by the VIIRS DNB, we present methods for reducing processing time.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 2313-433X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1400
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Author Sánchez de Miguel, A.; Bará, S.; Aubé, M.; Cardiel, N.; Tapia, C.E.; Zamorano, J.; Gaston, K.J.
Title Evaluating Human Photoreceptoral Inputs from Night-Time Lights Using RGB Imaging Photometry Type Journal Article
Year 2019 Publication Journal of Imaging Abbreviated Journal J. Imaging
Volume 5 Issue 4 Pages 49
Keywords Human Health; Remote Sensing; Instrumentation
Abstract Night-time lights interact with human physiology through different pathways starting at the retinal layers of the eye; from the signals provided by the rods; the S-, L- and M-cones; and the intrinsically photosensitive retinal ganglion cells (ipRGC). These individual photic channels combine in complex ways to modulate important physiological processes, among them the daily entrainment of the neural master oscillator that regulates circadian rhythms. Evaluating the relative excitation of each type of photoreceptor generally requires full knowledge of the spectral power distribution of the incoming light, information that is not easily available in many practical applications. One such instance is wide area sensing of public outdoor lighting; present-day radiometers onboard Earth-orbiting platforms with sufficient nighttime sensitivity are generally panchromatic and lack the required spectral discrimination capacity. In this paper, we show that RGB imagery acquired with off-the-shelf digital single-lens reflex cameras (DSLR) can be a useful tool to evaluate, with reasonable accuracy and high angular resolution, the photoreceptoral inputs associated with a wide range of lamp technologies. The method is based on linear regressions of these inputs against optimum combinations of the associated R, G, and B signals, built for a large set of artificial light sources by means of synthetic photometry. Given the widespread use of RGB imaging devices, this approach is expected to facilitate the monitoring of the physiological effects of light pollution, from ground and space alike, using standard imaging technology.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN (down) 2313-433X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2294
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Author Jechow, A.; Kyba, C.; Hölker, F.
Title 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.
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Language Summary Language Original Title
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ISSN (down) 2313-433X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2327
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