VJ102DNB - VIIRS/JPSS1 Day/Night Band Moderate Resolution 6-Min L1B Swath 750m

VJ102DNB is the short-name of the Joint Polar-orbiting Satellite System-1 (JPSS-1/NOAA20; referred to hereafter as J1) 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 3060 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 3232 lines by 4064 pixels.

The variables in the observation data in the J1-derived VIIRS L1B calibration product are almost similar to those from the SNPP-VIIRS L1B (collection-1) except for one major change: The J1 VIIRS L1B 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).