scholarly journals Reducing Variability and Removing Natural Light from Nighttime Satellite Imagery: A Case Study Using the VIIRS DNB

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3287 ◽  
Author(s):  
Jacqueline Coesfeld ◽  
Theres Kuester ◽  
Helga U. Kuechly ◽  
Christopher C. M. Kyba
Keyword(s):  
Web Application ◽  
Infrared Imaging ◽  
Light Emission ◽  
Natural Light ◽  
Artificial Light ◽  
Light Sources ◽  
Data Services ◽  
The Earth ◽  
Using Data

Temporal variation of natural light sources such as airglow limits the ability of night light sensors to detect changes in small sources of artificial light (such as villages). This study presents a method for correcting for this effect globally, using the satellite radiance detected from regions without artificial light emissions. We developed a routine to define an approximate grid of locations worldwide that do not have regular light emission. We apply this method with a 5 degree equally spaced global grid (total of 2016 individual locations), using data from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day-Night Band (DNB). This code could easily be adapted for other future global sensors. The correction reduces the standard deviation of data in the Earth Observation Group monthly DNB composites by almost a factor of two. The code and datasets presented here are available under an open license by GFZ Data Services, and are implemented in the Radiance Light Trends web application.

scholarly journals Response of Polycrystalline Solar Cell Outputs to Visible Spectrum and other Light Sources-a Case Study

2018 ◽  
Vol 8 (6) ◽  
pp. 4096
Author(s):  
Ayman Y. Al-Rawashdeh ◽  
Omar Albarbarawi ◽  
Ghazi Qaryouti
Keyword(s):  
Solar Cells ◽  
Visible Spectrum ◽  
Artificial Light ◽  
Light Sources ◽  
Variable Response ◽  
Artificial Illumination ◽  
Different Color ◽  
Color Filters ◽  
Sunlight Radiation

<p>In this case study, two polycrystalline solar modules were installed outdoors (irradiated by sunlight) and indoors (irradiated by artificial lights). The solar cells in both cases were installed using different color filters that allowed the passage of certain light frequencies. The amount of energy produced by each module were measured and compared to a reference module with no filter. The results indicated the variable response of polycrystalline solar cells to natural and artificial light sources, being more responsive in both cases to red band color as could be deduced from their % current outputs (72.5% sunlight radiation; 84.38% artificial light sources). Other colors, including yellow, green, orange and violet afforded acceptable outputs. The results indicated that electrical outputs of indoor solar cells decreased when colored filters were used, but red filter in general afforded the maximum outputs, for both the artificially radiated indoor and naturally radiated outdoor solar cells. The case study suggests the possible complementary advantage of using indoor mounted solar cells for the production of electricity during artificial illumination period of the day.</p>

scholarly journals A Case Study of Explosion a Single Solar Burst Type III and IV due to Active Region AR1890

2014 ◽  
Vol 38 ◽  
pp. 171-180 ◽  
Author(s):  
Zety Sharizat Hamidi ◽  
M.B. Ibrahim ◽  
N.N.M. Shariff ◽  
C. Monstein
Keyword(s):  
Active Region ◽  
Solar Flare ◽  
Comprehensive Description ◽  
Type Iii ◽  
Solar Burst ◽  
Type Iv ◽  
The Earth ◽  
Using Data

Using data from a BLEIN Callisto site, we aim to provide a comprehensive description of the synopsis formation and dynamics of a a single solar burst type III and IV event due to active region AR1890. This eruption has started since 14:15 UT with a formation of type III solar burst. To investigate the importance of the role of type III solar burst can potentially form a type IV solar burst, the literature review of both bursts is outlined in detailed. The orientation and position of AR1890 make the explosion of a class C-solar flare is not directly to the Earth. Nevertheless, it is clear that the interactions of others sunspots such as AR1893,AR1895,AR1896, AR1897 and AR1898 should be studied in detail to understand what makes the type III burst formed before the type IV solar burst.

scholarly journals Variation of Individual Location Radiance in VIIRS DNB Monthly Composite Images

2018 ◽  
Author(s):  
Jacqueline Coesfeld ◽  
Sharolyn Anderson ◽  
Kimberly Baugh ◽  
Christopher Elvidge ◽  
Harald Schernthanner ◽  
...  
Keyword(s):  
Large Scale ◽  
Infrared Imaging ◽  
Light Emission ◽  
Light Sources ◽  
Light Emitters ◽  
Local Factors ◽  
The Mean ◽  
The Stability ◽  
Night Lights ◽  
Monthly Variations

With the growing size and use of night lights time series from the Visible Infrared Imaging Radiometer Suite Day/Night Band (DNB), it is important to understand the stability of the dataset. All satellites observe differences in pixel values during repeat observations. In the case of night lights data, these changes can be due to both environmental effects and changes in light emission. Here we examine the stability of individual locations of particular large scale light sources (e.g. airports, prisons) in the monthly composites of DNB data from April 2012 to September 2017. The radiances for individual pixels of most large light emitters are approximately normally distributed, with a standard deviation of typically 15-20% of the mean. We observe geospatial autocorrelation in the monthly variations for nearby sites, while the correlation for sites separated by large distances is small. This suggests that local factors contribute most to the variation in the pixel radiances, and furthermore that averaging radiances over large areas will reduce the total variation. A better understanding of the causes of temporal variation would improve the sensitivity of DNB to lighting changes.

scholarly journals Rendering Spaces for Architectural Environments

1995 ◽  
Vol 4 (3) ◽  
pp. 286-296 ◽  
Author(s):  
Jeffry S. Nimeroff ◽  
Eero Simoncelli ◽  
Norman I. Badler ◽  
Julie Dorsey
Keyword(s):  
Virtual Environments ◽  
General Framework ◽  
Geometric Model ◽  
Natural Light ◽  
Artificial Light ◽  
Light Sources ◽  
Scene Description ◽  
The Given ◽  
New Framework

We present a new framework for rendering virtual environments. This framework is proposed as a complete scene description, which embodies the space of all possible renderings, under all possible lighting scenarios of the given scene. In effect, this hypothetical rendering space includes all possible light sources as part of the geometric model. While it would be impractical to implement the general framework, this approach does allow us to look at the rendering problem in a new way. Thus, we propose new representations that are subspaces of the entire rendering space. Some of these subspaces are computationally tractable and may be carefully chosen to serve a particular application. The approach is useful both for real and virtual scenes. The framework includes methods for rendering environments which are illuminated by artificial light, natural light, or a combination of the two models.

scholarly journals Are Individual Differences in Sleep and Circadian Timing Amplified by Use of Artificial Light Sources?

2017 ◽  
Vol 32 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Krithika Swaminathan ◽  
Elizabeth B. Klerman ◽  
Andrew J. K. Phillips
Keyword(s):  
Natural Light ◽  
Artificial Light ◽  
Light Sources ◽  
Light Cycle ◽  
Circadian Period ◽  
Realistic Condition ◽  
Circadian Timing ◽  
Sleep Timing ◽  
Light Levels ◽  
Circadian Physiology

Within the human population, there is large interindividual variability in the timing of sleep and circadian rhythms. This variability has been attributed to individual differences in sleep physiology, circadian physiology, and/or light exposure. Recent experimental evidence suggests that the latter is necessary to evoke large interindividual differences in sleep and circadian timing. We used a validated model of human sleep and circadian physiology to test the hypothesis that intrinsic differences in sleep and circadian timing are amplified by self-selected use of artificial light sources. We tested the model under 2 conditions motivated by an experimental study (Wright et al., 2013): (1) a “natural” light cycle, and (2) a “realistic” light cycle that included attenuation of light due to living indoors when natural light levels are high and use of electric light when natural light levels are low. Within these conditions, we determined the relationship between intrinsic circadian period (within the range of 23.7-24.6 h) and timing of sleep onset, sleep offset, and circadian rhythms. In addition, we simulated a work week, with fixed wake time for 5 days and free sleep times on weekends. Under both conditions, a longer intrinsic period resulted in later sleep and circadian timing. Compared to the natural condition, the realistic condition evoked more than double the variation in sleep timing across the physiological range of intrinsic circadian periods. Model predictions closely matched data from the experimental study. We found that if the intrinsic circadian period was long (>24.2 h) under the realistic condition, there was significant mismatch in sleep timing between weekdays and weekends, which is known as social jetlag. These findings indicate that individual tendencies to have very delayed schedules can be greatly amplified by self-selected modifications to the natural light/dark cycle. This has important implications for therapeutic treatment of advanced or delayed sleep phase disorders.

scholarly journals Anatomy and micromorphometric analysis of leaf Catasetum x apolloi Benelli & Grade with addition of potassium silicate under different light sources

2017 ◽  
Vol 77 (1) ◽  
pp. 140-149 ◽  
Author(s):  
L. Eburneo ◽  
N. G. Ribeiro-Júnior ◽  
I. V. Karsburg ◽  
A. A. B. Rossi ◽  
I. V. Silva
Keyword(s):  
Culture Medium ◽  
Stomatal Density ◽  
Potassium Silicate ◽  
Natural Light ◽  
Artificial Light ◽  
Light Sources ◽  
Blade Thickness ◽  
Alternative Culture ◽  
Lower Light

Abstract The aim of this study was to compare vitroplants Catasetum x apolloi grown under natural light and artificial light and different concentrations of potassium silicate, providing data on the anatomical differentiation that aids the acclimatization process of this species. Plants from in vitro seeding were used; 5 protocorms of approximately 0.5 cm were inoculated into vials with a capacity of 500 mL containing 100 mL of alternative culture medium plus potassium silicate (0.0, 0.5; 1.0 mL L–1), pH adjusted to 5.5 ± 0.5 and gelated with 4GL–1 agar before the autoclaving process. Cultures were maintained under natural light (TNE) and artificial light (TAE) for 90 days, and micromorphometric analysis was performed for polar and equatorial diameter, density and stomatal index, blade thickness in the central rib, and secondary veins. Applications in K2SiO4 alternative medium provided the following: elongation of the hypodermis, thicker mesophyll, and more prominent midrib; elipptical guard cells; formation of epistomatal chamber; and lower stomatal density and stomatal with lower equatorial and polar diameters. The conditions that favored the acclimatization were lower light intensities and lower potassium silicate doses.

scholarly journals Variation of Individual Location Radiance in VIIRS DNB Monthly Composite Images

2018 ◽  
Vol 10 (12) ◽  
pp. 1964 ◽  
Author(s):  
Jacqueline Coesfeld ◽  
Sharolyn Anderson ◽  
Kimberly Baugh ◽  
Christopher Elvidge ◽  
Harald Schernthanner ◽  
...  
Keyword(s):  
Time Series ◽  
Large Scale ◽  
Infrared Imaging ◽  
Light Emission ◽  
Light Sources ◽  
Light Emitters ◽  
Local Factors ◽  
The Mean ◽  
The Stability ◽  
Monthly Variations

With the growing size and use of night light time series from the Visible Infrared Imaging Radiometer Suite Day/Night Band (DNB), it is important to understand the stability of the dataset. All satellites observe differences in pixel values during repeat observations. In the case of night light data, these changes can be due to both environmental effects and changes in light emission. Here we examine the stability of individual locations of particular large scale light sources (e.g., airports and prisons) in the monthly composites of DNB data from April 2012 to September 2017. The radiances for individual pixels of most large light emitters are approximately normally distributed, with a standard deviation of typically 15–20% of the mean. Greenhouses and flares, however, are not stable sources. We observe geospatial autocorrelation in the monthly variations for nearby sites, while the correlation for sites separated by large distances is small. This suggests that local factors contribute most to the variation in the pixel radiances and furthermore that averaging radiances over large areas will reduce the total variation. A better understanding of the causes of temporal variation would improve the sensitivity of DNB to lighting changes.

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