NASA’s recent release of a new Earth at night composite image is the first release of a new global map of night light distribution since 2012. Since their previous release, NASA has worked on an improvement of the underlying algorithms that provide clearer and more accurate imagery from the raw satellite data.
The latest version (shown as a small inset map in this cartogram feature) is not only the most accurate picture of light intensity around the globe, but the underlying data also allows a direct comparison of the changes that occurred between 2012 and 2016. For achieving this, the datasets of the two years were corrected for the changing light effects caused by the moon as well as “seasonal vegetation, clouds, aerosols, snow and ice cover, and even faint atmospheric emissions (such as airglow and auroras)” which “change the way light is observed in different parts of the world”. Both datasets also cover the period of a full year to take seasonal changes into account.

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