The Near Real Time (NRT) VIIRS Level 1 and Level 2 swath (VJ202DNB_NRT) product is 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.

For more information download VIIRS Level 1 Product User's Guide at:
https://ladsweb.modaps.eosdis.nasa.gov/api/v2/content/archives/Document Archive/Science Data Product Documentation/Processing and Algorithm Version History/NASA_VIIRS_L1B_UG_August_2021.pdf