The VIIRS Day-Night Band (DNB), with a spectral bandwidth of 500-900 nm, collects data at three different gain stages: low, mid, and high gain (LG, MG, and HG), covering a very large dynamic range and capable of sensing reflected light from space during both day and nighttime. This paper describes the use of stars for VIIRS DNB HG calibration, discusses some of the challenges and limits to this approach, and demonstrates various strategies and techniques developed for its calibration stability monitoring and results of calibration inter-comparisons among three VIIRS instruments currently operated on the S-NPP, NOAA-20, and newly launched NOAA-21.
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