Ground-based hyperspectral analysis of the urban nightscape

Álamús, Ramón; Bará, Salvador; Corbera, Jordi; Escofet, Jaume; Palà, Vicenç; Pipia, Luca; Tardà, Anna

doi:10.1016/j.isprsjprs.2016.12.004

Cited by 36 publications

(21 citation statements)

References 44 publications

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“…Recent studies have determined the spectral irradiance with spatially single channel sensors of the sky 26 and even under water 50 showing the dramatic alteration of the night light climate. Other recent work includes the use of hyperspectral imaging systems to determine the (direct) light available in an urban setting 51 .…”

Section: Discussionmentioning

confidence: 99%

Imaging and mapping the impact of clouds on skyglow with all-sky photometry

Jechow

Kollath

Ribas

et al. 2017

Sci Rep

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Artificial skyglow is constantly growing on a global scale, with potential ecological consequences ranging up to affecting biodiversity. To understand these consequences, worldwide mapping of skyglow for all weather conditions is urgently required. In particular, the amplification of skyglow by clouds needs to be studied, as clouds can extend the reach of skyglow into remote areas not affected by light pollution on clear nights. Here we use commercial digital single lens reflex cameras with fisheye lenses for all-sky photometry. We track the reach of skyglow from a peri-urban into a remote area on a clear and a partly cloudy night by performing transects from the Spanish town of Balaguer towards Montsec Astronomical Park. From one single all-sky image, we extract zenith luminance, horizontal and scalar illuminance. While zenith luminance reaches near-natural levels at 5 km distance from the town on the clear night, similar levels are only reached at 27 km on the partly cloudy night. Our results show the dramatic increase of the reach of skyglow even for moderate cloud coverage at this site. The powerful and easy-to-use method promises to be widely applicable for studies of ecological light pollution on a global scale also by non-specialists in photometry.

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Section: Discussionmentioning

confidence: 99%

Imaging and mapping the impact of clouds on skyglow with all-sky photometry

Jechow

Kollath

Ribas

et al. 2017

Sci Rep

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“…There have been very few studies regarding nightscape design while daytime landscape design studies [37] continue to be analyzed. Studies related to existing nightscape studies have been mainly focused on light itself [38,39] or images on nightscapes [40,41]. The nightscape, complete with awe-inspiring atmospheric events and potentially restorative fascinating stellar views, requires more empirical investigation [42].…”

Section: Nightscape Designmentioning

confidence: 99%

“…The physical environment settings for improving usability at night can be further improved by seizing which parts are more fearful or pleasing. Recent research presents the possibility to measure nightscape using sophisticated technology (e.g., airborne hyperspectral cameras [38]). In sum, various studies comparing perceived nightscape and measured nightscape by various tools present new possibilities for enhancing the quality of nightscapes.…”

Section: Nightscape Designmentioning

confidence: 99%

Use of Electroencephalography (EEG) for the Analysis of Emotional Perception and Fear to Nightscapes

Kim

Cheon

Kang³

2019

Sustainability

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As the necessity for safety and aesthetic of nightscape have arisen, the importance of nightscapes (i.e., nighttime landscape) planning has garnered the attention of mainstream consciousness. Therefore, this study was to suggest the guideline for nightscape planning using electroencephalography (EEG) technology and survey for recognizing the characteristics of a nightscape. Furthermore, we verified the electroencephalography (EEG) method as a tool for landscape evaluation. Therefore, this study analyzed the change of relative alpha wave and relative beta wave and perceived fear of participants depending on twelve nightscape settings (four types of settings: Built nightscape images group with an adult; Built nightscape images groups without an adult; Nature-dominant nightscape images with an adult; and Nature-dominant nightscape images without an adult). Our findings indicate that the most fearful nightscape setting was recorded in Built nightscape images groups without an adult figure in perceived fear result depending on four types of nightscape settings. In Nature-dominant nightscape images, on the other hand, the nightscape setting with an adult figure was more fearful than the setting without an adult. The interaction effect between landscape type (built and nature-dominant) and adult presence towards perceived fear was verified and it showed that the image with adult affects landscape type. For electroencephalography (EEG) results, several brain activities in the relative alpha and beta wave showed significant differences depending on nightscape settings, which situates electroencephalography (EEG) as an invaluable tool for evaluating landscapes. Based on our physiological electroencephalography (EEG) experiment, we provide a new analytic view of the nightscape. The approach we utilized enables a deeper understanding of emotional perception and fear among human subjects by identifying the physical environment which impacts how they experience nightscapes.

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“…Notwithstanding these limitations, our results suggest that RGB photometry with DSLR cameras can be a useful technique for obtaining relevant information on the physiological inputs to the eye in the lit nightscape. Although DSLR cameras cannot compete in spectral resolution with hyperspectral devices such as the ones that have been successfully employed in this field of research (see [54] regarding the use of hyperspectral cameras for urban lamp identification in New York, and [55] for their application to the determination of the streetlights band-weighted radiances Cy, Me, Rh, Ch, and Er in the Barcelona nightscape, and the resulting band-weighted irradiances at the eye of the city dwellers), DSLR offer clear advantages in terms of overall sensitivity and cost, with the same high angular resolution capability. The fact that a high number of photographers, astrophotographers and citizen scientists alike, besides the professional light pollution research community, are frequent DSLR users, can help to expand significantly the present capacity of acquiring extensive datasets for assessing physiological responses, information of key importance for epidemiologic studies addressing the health effects of human exposure to light at night.…”

Section: Discussionmentioning

confidence: 99%

Evaluating Human Photoreceptoral Inputs from Night-Time Lights Using RGB Imaging Photometry

Miguel

Bará

Aubé

et al. 2019

Preprint

Self Cite

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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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Ground-based hyperspectral analysis of the urban nightscape

Cited by 36 publications

References 44 publications

Imaging and mapping the impact of clouds on skyglow with all-sky photometry

Imaging and mapping the impact of clouds on skyglow with all-sky photometry

Use of Electroencephalography (EEG) for the Analysis of Emotional Perception and Fear to Nightscapes

Evaluating Human Photoreceptoral Inputs from Night-Time Lights Using RGB Imaging Photometry

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