|   | 
Details
   web
Records
Author Kolláth, Z.; Cool, A.; Jechow, A.; Kolláth, K.; Száz, D.; Tong, K.P.
Title Introducing the Dark Sky Unit for multi-spectral measurement of the night sky quality with commercial digital cameras Type Journal Article
Year 2020 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 253 Issue Pages 107162
Keywords Skyglow; Instrumentation; Measurement; light pollution; Radiometry
Abstract Multi-spectral imaging radiometry of the night sky provides essential information on light pollution (skyglow) and sky quality. However, due to the different spectral sensitivity of the devices used for light pollution measurement, the comparison of different surveys is not always trivial. In addition to the differences between measurement approaches, there is a strong variation in natural sky radiance due to the changes of airglow. Thus, especially at dark locations, the classical measurement methods (such as Sky Quality Meters) fail to provide consistent results. In this paper, we show how to make better use of the multi-spectral capabilities of commercial digital cameras and show their application for airglow analysis. We further recommend a novel sky quality metric the ”Dark Sky Unit”, based on an easily usable and SI traceable unit. This unit is a natural choice for consistent, digital camera-based measurements. We also present our camera system calibration methodology for use with the introduced metrics.
Address ELTE BDPK, Szombathely, Department of Physics, Hungary; zkollath(at)gmail.com
Corporate Author (up) Thesis
Publisher Elsever Place of Publication Elsevier Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4073 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2998
Permanent link to this record
 

 
Author de Meester, J.; Storch, T.
Title Optimized Performance Parameters for Nighttime Multispectral Satellite Imagery to Analyze Lightings in Urban Areas Type Journal Article
Year 2020 Publication Sensors (Basel, Switzerland) Abbreviated Journal Sensors (Basel)
Volume 20 Issue 11 Pages
Keywords Instrumentation; Remote Sensing; high spatial resolution; lighting parameter; lighting type classification; multispectral band optimization; nighttime remote sensing; satellite image simulation; urban area
Abstract Contrary to its daytime counterpart, nighttime visible and near infrared (VIS/NIR) satellite imagery is limited in both spectral and spatial resolution. Nevertheless, the relevance of such systems is unquestioned with applications to, e.g., examine urban areas, derive light pollution, and estimate energy consumption. To determine optimal spectral bands together with required radiometric and spatial resolution, at-sensor radiances are simulated based on combinations of lamp spectra with typical luminances according to lighting standards, surface reflectances, and radiative transfers for the consideration of atmospheric effects. Various band combinations are evaluated for their ability to differentiate between lighting types and to estimate the important lighting parameters: efficacy to produce visible light, percentage of emissions attributable to the blue part of the spectrum, and assessment of the perceived color of radiation sources. The selected bands are located in the green, blue, yellow-orange, near infrared, and red parts of the spectrum and include one panchromatic band. However, these nighttime bands tailored to artificial light emissions differ significantly from the typical daytime bands focusing on surface reflectances. Compared to existing or proposed nighttime or daytime satellites, the recommended characteristics improve, e.g., classification of lighting types by >10%. The simulations illustrate the feasible improvements in nocturnal VIS/NIR remote sensing which will lead to advanced applications.
Address German Aerospace Center (DLR), Earth Observation Center (EOC), Munchener Str. 20, 82234 Wessling, Germany
Corporate Author (up) 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 1424-8220 ISBN Medium
Area Expedition Conference
Notes PMID:32532117 Approved no
Call Number GFZ @ kyba @ Serial 3006
Permanent link to this record
 

 
Author Li, X.; Levin, N.; Xie, J.; Li, D.
Title Monitoring hourly night-time light by an unmanned aerial vehicle and its implications to satellite remote sensing Type Journal Article
Year 2020 Publication 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.
Address
Corporate Author (up) 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 3014
Permanent link to this record
 

 
Author Tabaka, P.
Title Pilot Measurement of Illuminance in the Context of Light Pollution Performed with an Unmanned Aerial Vehicle Type Journal Article
Year 2020 Publication Remote Sensing Abbreviated Journal Remote Sensing
Volume 12 Issue 13 Pages 2124
Keywords Instrumentation; Remote Sensing
Abstract This article presents the methodology and results of pilot field illuminance measurements using an unmanned aerial vehicle (UAV). The main goal of the study was to quantify the luminous flux emitted in the upper hemisphere (toward the sky) based on obtained measurement data. The luminous flux emitted toward the sky is the source of undesirable light pollution. For test purposes, a height-adjustable mobile park lantern was constructed, at the top of which any type of luminaire can be installed. In the pilot measurements, two real opal sphere-type luminaires were considered. The lantern was situated in an open area located away from a large city agglomeration. To determine the unusable luminous flux, illuminance was measured, placing the necessary measuring equipment on board a UAV. The measurements were supplemented with the registration of illuminance on the ground upon which the lantern was installed. Based on these data, the useful luminous flux was calculated. The findings show that UAVs may be successfully used for the assessment of the influence of lighting on the light pollution effect.
Address
Corporate Author (up) Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2072-4292 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 3040
Permanent link to this record
 

 
Author Ribas, S. J.; Aubé, M.; Bará, S.; Bouroussis, C.; Canal-Domingo, R.; Espey, B.; Hänel, A.; Jechow, A.; Kolláth, Z.; Marti, G.; Massana, P.; Schmidt, W.; Spoelstra, H.; Wuchterl, G.; Zamorano, J.; Kyba, C.
Title Report of the 2016 STARS4ALL/LoNNe Intercomparison Campaign Type Report
Year 2017 Publication Abbreviated Journal
Volume Issue Pages
Keywords Skyglow; Instrumentation
Abstract The 2016 LoNNe (Loss of the Night Network) intercomparison campaign is the fourth of four campaigns planned during EU COST Action ES1204. The first campaign took place in 2013 in Lastovo, Croatia, the second in Madrid, Spain (Bará et al 2015), the third in Torniella and Florence, Italy (Kyba et al 2015a). The 2016 campaign took place at the Parc Astronòmic Montsec (PAM). The campaign continued the strategy of taking measurements at multiple sites, this year with a main fixed site and then excursions to other sites. The goals of the campaigns included:

● Understanding the difference between extinction measurements made by DSLR photometry and classical astronomical (telescope) photometry, and also understanding the relation between extinction and sky brightness at these two sites.

● Examining the difference in radiance measured with the mosaic technique of the US National Parks Service camera compared to all-sky fisheye imagery

● Examining the relationships between all-sky and zenith radiance reported by different instruments

● Quantifying the sky brightnes at the sites, including full zenith spectral radiance at selected locations

● Measuring the systematic uncertainty on handheld SQM observations due to unit-to-unit differences
Address
Corporate Author (up) Thesis
Publisher GFZ Data Services Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 3057
Permanent link to this record