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Full catalog/VJ143DNBA1
VJ143DNBA1·v002·dataset

How much sunlight the land reflects, model inputs (VIIRS NOAA-20, 1 km)

VIIRS/JPSS1 DNB BRDF/Albedo Model Parameters Daily L3 Global 1km SIN Grid V002
land NASA LPCLOUD Level 3 active HDF-EOS5
In plain English

What it measures. Model settings that describe how the land surface reflects light depending on the angle of the sun and the viewing angle, at 1-kilometer detail, based on the day/night band that captures dim light.

How it's made. Produced daily from 16 days of VIIRS data on the NOAA-20 satellite, fitting a reflectance model to the observations to create these parameters.

How & where you'd use it. A technical building block: scientists plug these parameters into formulas to calculate surface brightness (albedo) at any sun angle; it is mainly used to make higher-level albedo products rather than directly.

What's measured

LAND SURFACE › SURFACE RADIATIVE PROPERTIES › REFLECTANCELAND SURFACE › SURFACE RADIATIVE PROPERTIES › ALBEDOLAND SURFACE › SURFACE RADIATIVE PROPERTIES › ANISOTROPY

Coverage & cadence

  • Time span2018-01-05 → ongoing
  • Measured byNOAA-20 (VIIRS)
  • Processing levelLevel 3
  • Spatial extent-180, -90, 180, 90
  • FormatsHDF-EOS5
  • StatusACTIVE

What you can do with it

  • Track deforestation, fire scars and land-cover change
  • Monitor crop and vegetation health (NDVI/EVI)
  • Map how built-up vs. green an area is over time
Official description

The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) Bidirectional Reflectance Distribution Function (BRDF) and Albedo Model Parameters (VJ143DNBA1) Version 2 product provides BRDF/Albedo model parameters at 1 kilometer (km) resolution. The VJ143DNBA1 product is produced daily using 16 days of VIIRS data and is weighted temporally to the ninth day, which is reflected in the file name. The VJ143 data products are designed to promote the continuity of NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF/Albedo data product suite. The VJ143 algorithm uses the RossThick/Li-Sparse-Reciprocal (RTLSR) semi-empirical kernel-driven BRDF model, with the three kernel weights from VJ143DNBA1 to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry ([VJ143DNBA4](https://doi.org/10.5067/VIIRS/VJ143DNBA4.002)), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) ([VJ143DNBA3](https://doi.org/10.5067/VIIRS/VJ143DNBA3.002)). Researchers can use the BRDF model parameters with a simple polynomial to obtain black-sky albedo at any solar illumination angle. Likewise, both the BSA and WSA Science Dataset (SDS) variables can be used with a simple polynomial to manually estimate instantaneous actual albedo (blue-sky albedo). Additional details regarding the methodology are available in the Algorithm Theoretical Basis Document (ATBD). The VJ143DNBA1 data product provides two SDS variables for mandatory quality and model parameters representing fiso, fvol, and fgeo for the VIIRS DNB. A low-resolution browse is also available showing BRDF/Albedo parameters for the DNB as a red, green, blue (RGB) image in JPEG format. Known Issues * For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS).

Get the data

vj143dnba1_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VJ143DNBA1",
    version="002",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from LPCLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.