For most applications that use nighttime lights, people are interested in the radiance at or near ground level, not necessarily what the radiance directly measured in space. While the top- and bottom-of-atmosphere radiances are clearly related in some way, they aren't directly proportional to each other. Many factors such as obstacles (e.g. tall buildings) or surface snow cover influence the radiance observed in space. Because of this, there are dramatic changes from night to night in the radiance observed from a single Black Marble pixel.
This page provides brief overviews of all of the factors that are known to affect night lights data. A more detailed description of several of these factors is provided by Wang et al. (2021) for VIIRS-DNB. Coesfeld et al. () showed that the radiance uncertainty grows roughly proportionally with radiance for
Two other papers that discuss the variability of DNB data are Coesfeld et al. (2018) and Tan et al. (2023).
This section below is still under construction
Sum of lights
List of sources of uncertainty with brief information: - BY CEREMA AND CHRIS