关于这张图
This image of part of the Atlantic coast of South America was acquired by the Suomi NPP satellite on the night of July 20, 2012. The image was made possible by the “day-night band” of the Visible Infrared Imaging Radiometer Suite (VIIRS), which detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe dim signals such as city lights, gas flares, auroras, wildfires, and reflected moonlight. “Nothing tells us more about the spread of humans across the Earth than city lights,” says Chris Elvidge, who leads the Earth Observation Group at NOAA’s N…