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Full catalog/VJ203MOD
VJ203MOD·v2.1·dataset

Where each pixel sits on Earth, a helper file (VIIRS NOAA-21)

VIIRS/JPSS2 Moderate Resolution Terrain-Corrected Geolocation 6-Min L1 Swath 750m V2.1
land NASA LAADS Level 1A active netCDF-4
In plain English

What it measures. A helper file that pins down exactly where on Earth each image pixel falls, including latitude, longitude, ground height, and the angles of the Sun and sensor for every pixel.

How it's made. Computed for the VIIRS instrument on the NOAA-21 satellite using the satellite's position and pointing along with an Earth and terrain model, at 750-meter resolution.

How & where you'd use it. A behind-the-scenes building block that lets other VIIRS image products be correctly placed on the map; rarely used on its own.

What's measured

SPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › INFRARED RADIANCESPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › REFLECTED INFRAREDSPECTRAL/ENGINEERING › SENSOR CHARACTERISTICS › GEOLOCATIONSPECTRAL/ENGINEERING › VISIBLE WAVELENGTHS › VISIBLE RADIANCE

Coverage & cadence

  • Time span2023-02-10 → ongoing
  • Measured byNOAA-21 (VIIRS)
  • Processing levelLevel 1A
  • Spatial extent-180, -90, 180, 90
  • FormatsnetCDF-4
  • 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 VIIRS/JPSS2 Moderate Resolution Terrain Corrected Geolocation 6-Min L1 Swath 750 m, short-name VJ203MOD is the Joint Polar-orbiting Satellite System-2 (JPSS-2/NOAA-21) platform-based NASA Visible-Infrared Imaging-Radiometer Suite (VIIRS) L1 terrain-corrected geolocation product, and contains the derived line-of-sight (LOS) vectors for each of the 750-m moderate-resolution, or M-bands. The geolocation algorithm uses a number of inputs that include an Earth ellipsoid, geoid, and a digital terrain model along with the SNPP platform’s ephemeris and attitude data, and knowledge of the VIIRS sensor and satellite geometry. It produces geodetic coordinates (latitude and longitude), and related parameters for each VIIRS L1 pixel. The VJ203MOD product includes geodetic latitude, longitude, surface height above the geoid, solar zenith and azimuth angles, sensor zenith and azimuth angles, land/water mask, and quality flag for every pixel location. VJ203MOD provides a fundamental input to derive a number of VIIRS M-band higher-level products. The J2 VIIRS geolocation underwent an on-orbit validation. Geolocation errors of about 350 m in the along-scan direction and about 165 m in the along-track direction were corrected for the image-resolution bands and moderate-resolution bands. The Day-Night band (DNB) geolocation error of about 2000 m was corrected. For more information and documents, visit LAADS product page at: https://ladsweb.modaps.eosdis.nasa.gov/missions-and-measurements/products/VJ203MOD

Get the data

vj203mod_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VJ203MOD",
    version="2.1",
    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 LAADS
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.