Quantifying uncertainties in nighttime light retrievals from Suomi-NPP and NOAA-20 VIIRS Day/Night Band data

Wang, Zhuosen; Román, M. O.; Kalb, Virginia; Miller, Steven D.; Zhang, Jianglong; Shrestha, Ranjay

doi:10.1016/j.rse.2021.112557

Cited by 63 publications

(63 citation statements)

References 94 publications

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“…To reduce the bias introduced by the geographic mismatch of NTL imageries over days, the NTL radiance was averaged using a 3 x 3-pixel window as recommended in the literature [44]. However, despite the state-of-art correction strategy used to generate the Black Marble products, uncertainties remain in the NTL time series due to the relatively lower accuracy in nighttime atmospheric correction and cloud detection [45]. Therefore, the weekly maximum value, instead of the average value, of each pixel is extracted as the nighttime vitality proxy.…”

Section: B Vitality Proxy and Vitality Indicesmentioning

confidence: 99%

Nighttime Vitality and Its Relationship to Urban Diversity: An Exploratory Analysis in Shenzhen, China

Zhang

Liu

Tan

et al. 2022

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

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Relationship between urban diversity and urban vitality is imperative for guiding better design in urban development, though existing frameworks are not able to efficiently examine the relationship at multiple scales. In this article, we propose a new framework to integrate nighttime light (NTL) imagery and multisource urban data into multiscale geographically weighted regression (MGWR) models to examine the varying relationship between diversity and vitality across space and time. NTL is used as a proxy for urban nighttime vitality. Public transport, taxi transit, and points of interest (POI) data are used to derive three aspects of urban diversity indices: ridership diversity, spatial interaction diversity, and built environment diversity. By comparing the models in holiday and non-holiday weeks in Shenzhen, China, the NTL-based vitality proxy was found to be strongly correlated with the urban diversity indices, given by the satisfactory goodness of fit (r-squared = 0.9) of the MGWR models. The spatially varying relationships between diversity indices and nighttime vitality were observed and patterns discussed. The analysis of the coefficients revealed the importance of stable public transport and fluctuating taxi trips for nighttime vitality. The new index proposed for the diversity of spatial interaction (DSI) is a strong indicator for nighttime vitality, adding to existing vitality indicators. Furthermore, this study found that DSI and density of catering (DOC) have less temporal variation, indicating their robustness in measuring nighttime vitality. This study provided empirical insights into how nighttime vitality is related to urban diversity, demonstrating new applications of NTL for intracity studies.

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Section: B Vitality Proxy and Vitality Indicesmentioning

confidence: 99%

Nighttime Vitality and Its Relationship to Urban Diversity: An Exploratory Analysis in Shenzhen, China

Zhang

Liu

Tan

et al. 2022

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

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“…The 3D structure of artificially lit areas has a major impact on observations of artificial lights (Figures S2–S3 in Supporting Information ), as objects can partially or entirely block the view of a light source or surface reflection from above (Coesfeld et al., 2018; Levin et al., 2020; Tan et al., 2022; Wang et al., 2021). Geographic variations in the urban structure (e.g., height of buildings and width of streets) mean that the blocking effect varies within cities and between countries and continents (Elvidge et al., 2020).…”

Section: Evaluating Impact and Properties Of Artificial Lightsmentioning

confidence: 99%

“…The figure depicts observations of an unlit space located 2 km away from a single bright artificial light, viewed from different angles. Provided the source is bright enough, a sensor can detect light scattered by the atmosphere above the level of natural background (de Miguel et al., 2020; Wang et al., 2021). However, the radiance of scattered light depends on the viewing path, and here is larger when the path passes through the atmosphere above the source (Figures 2a and 2d).…”

Section: Remote Sensing Of Atmospheric and Earth Surface Propertiesmentioning

confidence: 99%

Multiple Angle Observations Would Benefit Visible Band Remote Sensing Using Night Lights

et al. 2022

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The spatial and angular emission patterns of artificial and natural light emitted, scattered, and reflected from the Earth at night are far more complex than those for scattered and reflected solar radiation during daytime. In this commentary, we use examples to show that there is additional information contained in the angular distribution of emitted light. We argue that this information could be used to improve existing remote sensing retrievals based on night lights, and in some cases could make entirely new remote sensing analyses possible. This work will be challenging, so we hope this article will encourage researchers and funding agencies to pursue further study of how multi-angle views can be analyzed or acquired.Plain Language Summary When satellites take images of Earth, they usually do so from directly above (or as close to it as is reasonably possible). In this comment, we show that for studies that use imagery of Earth at night, it may be beneficial to take several images of the same area at different angles within a short period of time. For example, different types of lights shine in different directions (street lights usually shine down, while video advertisements shine sideways), and tall buildings can block the view of a street from some viewing angles. Additionally, since views from different directions pass through different amounts of air, imagery at multiple angles could be used to obtain information about Earth's atmosphere, and measure artificial and natural night sky brightness. The main point of the paper is to encourage researchers, funding agencies, and KYBA ET AL.

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“…These studies indicate that the VIIRS-DNB may be capable of tracking the changes in human activity patterns associated with COVID-19, despite having an overpass around 1:30 am 31 . However, NTL time-series are not stationary 21 , 32 , so robust time-series analyses are needed that move beyond before-after snapshot comparisons of COVID’s impact. Furthermore, no studies have used NTL to explore the variation in responses to COVID-19 measures within and across countries, nor assessed their promise as a substitute or supplement for mobility over data-sparse regions.…”

Section: Introductionmentioning

confidence: 99%

Tracking COVID-19 urban activity changes in the Middle East from nighttime lights

Stokes

Román

2022

Sci Rep

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In response to the COVID-19 pandemic, governments around the world have enacted widespread physical distancing measures to prevent and control virus transmission. Quantitative, spatially-disaggregated information about the population-scale shifts in activity that have resulted from these measures is extremely scarce, particularly for regions outside of Europe and the US. Public health institutions often must make decisions about control measures with limited region-specific data about how they will affect societal behavior, patterns of exposure, and infection outcomes. The Visible Infrared Imaging Radiometer Suite Day/Night Band (VIIRS DNB), a new-generation space-borne low-light imager, has the potential to track changes in human activity, but the capability has not yet been applied to a cross-country analysis of COVID-19 responses. Here, we examine multi-year (2015–2020) daily time-series data derived from NASA’s Black Marble VIIRS nighttime lights product (VNP46A2) covering 584 urban areas, in 17 countries in the Middle East to understand how communities have adhered to COVID-19 measures in the first 4 months of the pandemic. Nighttime lights capture the onset of national curfews and lockdowns well, but also expose the inconsistent response to control measures both across and within countries. In conflict-afflicted countries, low adherence to lockdowns and curfews was observed, highlighting the compound health and security threats that fragile states face. Our findings show how satellite measurements can aid in assessing the public response to physical distancing policies and the socio-cultural factors that shape their success, especially in fragile and data-sparse regions.

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Quantifying uncertainties in nighttime light retrievals from Suomi-NPP and NOAA-20 VIIRS Day/Night Band data

Cited by 63 publications

References 94 publications

Nighttime Vitality and Its Relationship to Urban Diversity: An Exploratory Analysis in Shenzhen, China

Nighttime Vitality and Its Relationship to Urban Diversity: An Exploratory Analysis in Shenzhen, China

Multiple Angle Observations Would Benefit Visible Band Remote Sensing Using Night Lights

Tracking COVID-19 urban activity changes in the Middle East from nighttime lights

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