VJ102DNB is the short-name of the NOAA-20 — formerly called Joint Polar-orbiting Satellite System-1 (JPSS-1) — platform-derived single NASA VIIRS panchromatic Day-Night band (DNB) calibrated radiance product. The DNB is one of the M-bands with an at-nadir spatial resolution of 750-meters (across the entire scan). The panchromatic DNB’s spectral wavelength ranges from 0.5 µm to 0.9 µm. It facilitates measuring night lights, reflected solar/lunar lights with a large dynamic range between a low of a quarter moon illumination to the brightest daylight. The DNB attempts to maintain a nearly constant 750-m resolution over the entire 3,060 km orbital swath by resorting to an on-board aggregation method, which also renders the calibration of the DNB a challenge. Stray-light and other sources of noise (lunar illuminance, twilight, clouds, noisy scan-edges, etc.) affect the DNB quality, and warrant correction. Considered a major advance in low-light imaging, the VIIRS DNB owes its heritage to the Operational Linescan System (OLS) visible sensors that were part of the Defense Meteorological Satellite Program (DMSP) platforms since the 1970s. The image dimensions of the 750 m DNB product measure 3,232 lines by 4,064 pixels.

The variables in the observation data in the NOAA-20-derived VIIRS Level-1B calibration product are almost like those from the SNPP-VIIRS Level-1B (collection-1) except for one major change: The NOAA-20 VIIRS Level-1B calibration product’s quality flags include a detector quality flag with associated masks, their values, and meanings for all the bands (I, M, and DNB).