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Full catalog/VJ143D52
VJ143D52·v002·dataset

Whether reflected-sunlight pixels had snow (NOAA-20, daily)

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

What it measures. A simple flag for each roughly 1-km land patch saying whether snow was present ('snow') or absent ('snow-free') when the reflected-sunlight measurement was made.

How it's made. Derived from 16 days of VIIRS observations on the NOAA-20 satellite, updated daily and arranged on a global grid built for climate models.

How & where you'd use it. A companion layer that tells researchers whether a reflectance value came from bare ground or snow, which matters for energy-balance and climate studies.

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 Snow Status product (VJ143D52) 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). VJ143D52 contains the snow status quality layer, which identifies each pixel as either “Snow-free Albedo Retrieved” or “Snow Albedo Retrieved” for the acquisition period. 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

vj143d52_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VJ143D52",
    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.