Island-building activities detected by DNB on south china sea

摘要

A temporal change of lights from islands on the South China Sea was monitored by the Day/Night Band (DNB) of the visible infrared imaging radiometer (VIIRS) on the Suomi-NPP from 2014 to 2016. As the DNB data could be contaminated by the lunar lights reflected by clouds for half of each month, the DNB data around the new moon period were used to focus on detecting lights from the surface. DNB mean intensity from the reef and vessel activities was measured in a circular area with the radius of 5 km around each reef. The DNB mean intensity exhibited a marked increase at the beginning of dredging, a decrease when dredging ended, and then a gradual increase after termination of dredging, as ground facilities were built on Subi Reef and Mischief Reef. Fiery Cross Reef didn't show a clear distinction between dredging operations and construction of ground facilities.