The Joint Polar Satellite System (JPSS) program will feature the first fully calibrated low-light visible-band sensor available for operational applications. The ‘Day/Night Band' (DNB) sensor, included on the Visible/Infrared Imager/Radiometer Suite (VIIRS), follows on after four decades of low-light visible imagery from the Defense Meteorological Satellite Program's (DMSP) Operational Linescan System (OLS). Improvements to the DNB include modern calibration, higher spatial resolution, state-of-the-art radiometric resolution, and instrument baffling (stray light reduction). Also, the DNB will be co-located with numerous near- and thermal-infrared bands on the VIIRS focal plane array; this promises to revolutionize nighttime processing. In particular, the DNB will enable quantitative retrievals based on reflected moonlight--impossible from NOAA's Advanced Very High Resolution Radiometer (AVHRR), which is confined to infrared-only measurements. Here, we provide a brief overview of the VIIRS/DNB sensor which will fly on board the NPOESS Preparatory Project (NPP) satellite to be launched on October 25, 2011.

Examples illustrated, based largely on currently available OLS imagery, will include clouds/fog, dust/aerosols, snow cover, fires, lightning flashes, sea ice, human settlements, and even some forms of marine bioluminescence. A new model for the calculation of lunar irradiance (necessary for quantitative nighttime applications) will also be detailed. We will also present preliminary results on the spatial/temporal distribution of moonlight availability, based on simulated satellite orbits coupled to predicted celestial geometry and the aforementioned lunar irradiance model. Of particular relevance here are the operational impacts of the absence of the DNB sensor from the mid-morning/early-evening (0930/2130 local crossing times) orbit of the future operational polar-orbiting constellation.

Under optimistic assumptions, we may be able to show “first nightlight” examples of the DNB by conference time.