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Full catalog/VJ143MA1
VJ143MA1·v002·dataset

Surface reflectance/albedo model parameters, daily (VIIRS, NOAA-20, 1 km)

VIIRS/JPSS1 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. The mathematical settings that describe how the land surface reflects sunlight in different directions, updated daily at about 1-kilometer detail. These are the ingredients used to calculate how bright and reflective the surface is.

How it's made. Computed from 16 days of measurements by the VIIRS instrument on the NOAA-20 satellite, using a model that captures how reflection changes with viewing and sun angles.

How & where you'd use it. A building-block input that feeds finished albedo and reflectance products; researchers use it to derive how much sunlight the surface bounces back, which matters for climate and energy studies.

What's measured

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

Coverage & cadence

  • Time span2018-01-01 → 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 Model Parameters (VJ143MA1) Version 2 product provides BRDF/Albedo model parameters at 1 kilometer (km) resolution. The VJ143MA1 product is produced daily using 16-day VIIRS data and is weighted temporally to the 9th 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 VJ143MA1 to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry ([VJ143MA4](https://doi.org/10.5067/VIIRS/VJ143MA4.002)), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) ([VJ143MA3](https://doi.org/10.5067/VIIRS/VJ143MA3.002)). 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 VJ143MA1 data product provides a total of twenty-four SDS variables including: mandatory quality bands and three multi-dimensional model parameter bands representing fiso, fvol, and fgeo for VIIRS moderate resolution bands M1-M5, M7-M8, and M10-M11. A low-resolution browse is also provided showing BRDF/Albedo parameters for bands M5, M7, and M5 as an RGB image in JPEG format. Known Issues * Known issues for VIIRS BRDF/Albedo data products can be found on the [VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS).

Get the data

vj143ma1_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VJ143MA1",
    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.