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Full catalog/VJ143IA2
VJ143IA2·v002·dataset

Quality flags for surface reflectance albedo (NOAA-20, daily, 500 m)

VIIRS/JPSS1 BRDF/Albedo Quality Daily L3 Global 500m SIN Grid V002
land NASA LPCLOUD Level 3 active HDF-EOS5
In plain English

What it measures. Quality information for a companion product that measures how the land surface reflects sunlight. Rather than the reflectance values themselves, this tells you how trustworthy each reading is and how many clear observations went into it, at 500-meter resolution.

How it's made. Produced daily from the NOAA-20 satellite's VIIRS sensor, pooling 16 days of observations and centered on the ninth day, designed to continue NASA's long-running MODIS albedo record.

How & where you'd use it. A companion quality-check layer most people use alongside the actual reflectance and albedo products, to know which pixels to trust.

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 Quality (VJ143IA2) Version 2 product provides BRDF and Albedo quality at 500 meter (m) resolution. The VJ143IA2 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 VJ143IA2 product provides information regarding band quality and days of valid observation within a 16-day period for the VIIRS imagery bands. 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 [VJ143IA1](https://doi.org/10.5067/VIIRS/VJ143IA1.002) to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry ([VJ143IA4](https://doi.org/10.5067/VIIRS/VJ143IA4.002)), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) ([VJ143IA3](https://doi.org/10.5067/VIIRS/VJ143IA3.002)). 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 VJ143IA2 data product provides a total of eleven SDS variables including: BRDF/Albedo band quality (inversion information) and days of valid observation within a 16-day period for VIIRS imagery bands I1, I2, and I3, as well as land water type class flag, snow BRDF albedo class flag, local solar noon, albedo uncertainty and the platform name. 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

vj143ia2_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VJ143IA2",
    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.