An improved algorithm for VIIRS Day/Night Band (DNB) high gain stage (HGS) dark offset determination

摘要

With comprehensive analysis of the VIIRS DNB on-board calibrator blackbody (OBCBB) data and Earth View (EV) data, it is shown that the DNB OBCBB data can only track the dark current component of the DNB HGS EV dark offset. The DNB observation of deep space during the spacecraft pitch maneuver was also contaminated by star lights. With these acquired knowledge, we propose an improved algorithm for determining the DNB HGS dark offset that is both free from light contamination and capable of tracking drifts continously. The new algorithm is expected to improve the DNB radiometric performance at low radiance level.