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Full catalog/VNP43IA4
VNP43IA4·v002·dataset

True surface color, viewing-angle corrected (VIIRS, Suomi-NPP, 500 m)

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

What it measures. The land's true reflected color at 500-meter detail, adjusted so it looks as if viewed straight down from above, removing the distortions caused by the sun and satellite being at different angles.

How it's made. Made from VIIRS data on the Suomi-NPP satellite by using a mathematical model of how surfaces reflect light in different directions, fitted over 16 days and centered on the ninth day.

How & where you'd use it. Gives a stable, consistent view of surface color over time and also yields surface brightness (albedo) values, useful for vegetation monitoring, land-cover studies, and climate and energy-balance research.

What's measured

LAND SURFACE › SURFACE RADIATIVE PROPERTIES › REFLECTANCELAND SURFACE › SURFACE RADIATIVE PROPERTIES › ANISOTROPYLAND SURFACE › SURFACE RADIATIVE PROPERTIES › ALBEDO

Coverage & cadence

  • Time span2012-01-17 → ongoing
  • Measured bySuomi-NPP (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 NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Nadir Bidirectional Reflectance Distribution Function (BRDF) Adjusted Reflectance (NBAR) Version 2 product provides NBAR estimates at 500 meter (m) resolution. The VNP43IA4 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 view angle effects are removed from the directional reflectances, resulting in a stable and consistent NBAR product. The VNP43 data products are designed to promote the continuity of NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF/Albedo data product suite. The VNP43 algorithm uses the RossThick/Li-Sparse-Reciprocal (RTLSR) semi-empirical kernel-driven BRDF model, with the three kernel weights from [VNP43IA1](https://doi.org/10.5067/VIIRS/VNP43IA1.002) to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry (VNP43IA4), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) [(VNP43IA3)](https://doi.org/10.5067/VIIRS/VNP43IA3.002). 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 VNP43IA4 product includes six SDS variables for BRDF/Albedo mandatory quality and nadir reflectance for VIIRS imagery bands I1, I2, and I3. A low-resolution browse image is also available showing NBAR bands I1, I2, and I1 as an RGB (red, green, blue) 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

vnp43ia4_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VNP43IA4",
    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.