JPSS-2 VIIRS Day–Night Band Prelaunch Radiometric Calibration and Performance

The first two flight models of the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument continue to operate onboard the Suomi National Polar-Orbiting Partnership (S-NPP) and NOAA-20 spacecrafts. The third flight model is set to be launched as one of a complement of instruments onboard the Joint Polar-Orbiting Satellite System-2 (JPSS-2) satellite. In addition to its 14 reflective solar bands and seven thermal emissive bands, VIIRS has a unique day–night band (DNB). The DNB is a panchromatic imager based on CCD detectors, covering a spectral range of about 500–900 nm. The DNB is made up of three gain stages, allowing the sensor to operate over a large dynamic range (
$3 \times 10 ^{-9}$
–0.02 W/cm
²
/sr). As part of VIIRS prelaunch ground testing, the DNB has been characterized to determine its functionality and performance under a space-like environment. The results are compared against the design specification and with previous VIIRS flight models when applicable. This article presents a comprehensive summary of the VIIRS DNB prelaunch testing and the results of radiometric and spectral assessments. The expected impact on on-orbit operations and calibrated data products are also discussed.