Vicarious validation of straylight correction for VIIRS day/night band using Dome-C

Abstract

The Day/Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard Suomi National Polar-orbiting Partnership (Suomi-NPP) represents a major advancement in night time imaging capabilities. The VIIRS DNB sensor is affected by stray light. Straylight effect on the DNB instrument is due to solar illumination entering the optical path after the satellite passes through the day-night terminator projected on Earth’s surface. It results in an overall increase in the recorded radiance values. This effect is more significant during solstice. After the launch of Suomi-NPP in October 2011, there was a gray haze in radiance images observed by DNB due to straylight, and straylight correction has been implemented to remove this effect. This study performs vicarious validation of straylight correction for VIIRS DNB band using Dome C in Antarctic. Nadir observations of these high latitude regions by VIIRS are selected during perpetual night season, i.e. from April to July during the year 2014 under various lunar phases. The dependence of observed radiance over Dome C on lunar phases and the cross-comparison between DNB observations for events with/without straylight are shown in this paper. This paper presents an effective method to assess the performance of straylight correction for VIIRS DNB in Southern Hemisphere.