Suomi NPP VIIRS day-night band on-orbit performance

The Suomi National Polar-Orbiting Partnership (NPP) launched on 28 October 2011 hosts the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor. The VIIRS sensor includes a day-night band (DNB) that covers almost 7 orders of magnitude in its dynamic range from full sunlit scenes to lunar-illuminated clouds. The DNB is panchromatic and covers the wavelengths from 500 nm to 900 nm. Since launch, extensive effort has gone into its characterization. We have shown that the DNB is performing extremely well, meeting most of its specifications with some minor exceedances. The DNB characteristics evaluated include the following: sampling and resolution across the swath, geolocation uncertainty, radiometric sensitivity, radiometric uncertainty, and stray light. The only significant deviation from specification involves the stray light specification. On-orbit, the characterization shows that the DNB suffers stray light level on the order of 100% L-min or 3x10(-9) W.cm(-2).sr(-1). After algorithmic correction, the residual radiometric error was reduced to approximately 4.5x10(-10) W.cm(-2).sr(-1).