The Visible/ Infrared Imager Radiometer Suite (VIIRS) is a key NPOESS sensor. Key features of VIIRS radiometric performance are presented. The measured noise performance for each spectral band is presented. Known sensor artifacts such as: optical crosstalk, near and far field scatter and other scattering related artifacts are described and quantified. VIIRS performance at the Sensor Data Record (SDR) level is summarized using results from multiple orbit average scene simulation tools.