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Full catalog/VNP18C1
VNP18C1·v002·dataset

Sunlight reaching the surface daily (VIIRS, Suomi-NPP, 0.05°)

VIIRS/NPP Downward Shortwave Radiation Daily L3 Global 0.05Deg CMG V002
land NASA LPCLOUD Level 3 active HDF-EOS5
In plain English

What it measures. How much sunlight reaches the ground each day, measured across the full range of solar energy (the shortwave band). The numbers describe the incoming solar power hitting land surfaces.

How it's made. Produced from the VIIRS sensor on the Suomi-NPP satellite, with daily measurements combined onto a roughly 5-km global grid using look-up tables that account for clouds and haze.

How & where you'd use it. Important for solar energy planning and operations, and as an input to land models that track how plants and soil respond to sunlight.

What's measured

LAND SURFACE › SURFACE RADIATIVE PROPERTIES › REFLECTANCELAND SURFACE › SURFACE RADIATIVE PROPERTIES › ALBEDOLAND SURFACE › SURFACE RADIATIVE PROPERTIES › ANISOTROPYATMOSPHERE › ATMOSPHERIC RADIATION › SHORTWAVE RADIATION

Coverage & cadence

  • Time span2012-01-19 → 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 VNP18C1 Version 2 is a NASA/NOAA Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Downward Shortwave Radiation (DSR) Level 3 Climate Modeling Grid (CMG) product. It is produced at 0.05 degree pixel resolution at daily intervals. DSR is the incident solar radiation over land surfaces in the shortwave spectrum (300-4,000 nanometers) and is a significant variable in land surface models (LSMs), receiving increased attention due to its importance for the management and operation of solar energy systems. The VNP18 algorithm adapts the narrowband look-up table (LUT) approach to estimate DSR. The LUTs consider different types of loadings of aerosols and clouds at a variety of illumination and viewing geometry. The Algorithm Theoretical Basis Document (ATBD) is forthcoming and will provide additional details regarding the methodology used to create the data. The VNP18C1 product is aggregated from VNP18A1 files and includes one set of global 3-hour DSR variables and daily mean DSR.

Get the data

vnp18c1_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VNP18C1",
    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.