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Full catalog/VJ143D40
VJ143D40·v002·dataset

How much sunlight the ground reflects, quality (NOAA-20, daily)

VIIRS/JPSS1 BRDF/Albedo Quality Daily L3 Global 30ArcSec CMG V002
land NASA LPCLOUD Level 3 active HDF-EOS5
In plain English

What it measures. A grade-card for another dataset: for every roughly 1-km patch of land worldwide, it rates how trustworthy the measurements of reflected sunlight (and how that reflection changes with viewing angle) are for nine of the sensor's light-detecting bands plus its day/night band.

How it's made. Built from 16 days of observations by the VIIRS instrument on the NOAA-20 satellite, then refreshed daily and placed on a global grid sized for climate models.

How & where you'd use it. Mainly a companion layer: researchers check it to decide which reflectance and albedo pixels are reliable enough to use, rather than reading it on its own.

What's measured

LAND SURFACE › SURFACE RADIATIVE PROPERTIES › ALBEDOLAND SURFACE › SURFACE RADIATIVE PROPERTIES › ANISOTROPYLAND SURFACE › SURFACE RADIATIVE PROPERTIES › REFLECTANCE

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) Bidirectional Reflectance Distribution Function (BRDF) and Albedo Quality product (VJ143D40) is produced daily using 16 days of data at 30 arc second (1,000 meter) resolution. Data are temporally weighted to the ninth day, which is reflected in the file name. The VJ143D product suite is provided in a Climate Modeling Grid (CMG), which covers the entire globe for use in climate simulation models. Due to the large file size, each VJ143D product contains just one data layer for each of the parameters included in the [VJ143MA2](https://doi.org/10.5067/VIIRS/VJ143MA2.002) product. VJ143D40 through VJ143D53 are the 30 arc second BRDF/Albedo Quality values, the Local Solar Noon values, the Valid Observations of the moderate resolution bands (M1 through M5, M7, M8, M10, and M11) plus the Day/Night Band (DNB), the Snow Status, and the Uncertainty. Details regarding methodology are available on the VJ143MA2 product page and in the Algorithm Theoretical Basis Document (ATBD). VJ143D40 consists of BRDF/Albedo quality information representing the overall quality of each pixel for VIIRS moderate resolution bands M1 through M5, M7, M8, M10, M11, and DNB. 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).

Get the data

vj143d40_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VJ143D40",
    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.