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Collection 2 JPSS2 Product Descriptions: VJ202DNB_NRT

Last update: January 16, 2024

Data Set Short Name:
VJ202DNB_NRT

Data Set Long Name:
VIIRS/JPSS2 Day/Night Band 6-Min L1B Swath 750m NRT

Platform:
Joint Polar Satellite System-2 (JPSS-2/NOAA-21)

Instrument:
Visible-Infrared Imaging-Radiometer Suite (VIIRS)

Product Description:
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.

The J2 VIIRS radiometric calibration Level-1B reprocessing includes a few calibration updates for the reflective solar bands (RSB), but no significant changes for the day-night band (DNB) or thermal emissive bands (TEB).

The spatial resolution of the instrument at viewing nadir is approximately 750 m for the DNB and the Moderate-resolution Bands and and 375m for the Imagery bands. The DNB is aggregated to maintain nearly constant horizontal spatial resolution across the swath.

As the DNB is sensitive to nighttime radiation over the full lunar cycle, the incoming solar and lunar radiation must be properly modeled to calculate the reflectance. However, the DNB is sensitive to more sources of radiation than just the sun and moon.

For more information download VIIRS Level 1 Product User's Guide

file_naming_convention = VJ202DNB_NRT.AYYYYDDD.HHMM.CCC.nc

AYYYYDDD = Acquisition Year and Day of Year
HHMM = Acquisition Hour and Minute
CCC = Collection number
nc = NetCDF4

Production Frequency:
240 files per day

Spatial Coverage:
Global

Spatial Resolution:
750m at nadir

File Size (MB):
~40

Citation:
We kindly request that you cite the use of this data set in a publication using the following citation.

Author (PI), et al., 2024. Product name as given on web site. NASA MODIS Adaptive Processing System, Goddard Space Flight Center, USA: [link as given on product site].

For example:
Wolfe, R. E., G. Lin, M. Nishihama, K. P. Tewari, J. C. Tilton, and A. R. Isaacman (2013), Suomi NPP VIIRS prelaunch and on-orbit geometric calibration and characterization, J. Geophys. Res. Atmos., 118, 11508–11521, doi:10.1002/jgrd.50873.

Dataset Originator/Creator:
VIIRS Characterization Support Team (VCST)/ MODIS Adaptive Processing System (MODAPS)

Dataset DOI:
https://doi.org/10.5067/VIIRS/VJ202DNB_NRT.002