Pixel location helper file, near-real-time (VIIRS Suomi-NPP, 750 m)
What it measures. For every pixel a VIIRS sensor sees, this tells you exactly where on Earth it falls: latitude, longitude, surface height, the angles of the sun and satellite, and whether the spot is land or water.
How it's made. Calculated quickly (near-real-time) for the VIIRS instrument on the Suomi-NPP satellite by combining the spacecraft's position and pointing with a digital map of Earth's terrain.
How & where you'd use it. This is a behind-the-scenes input that other VIIRS products rely on to know where their measurements are located; most people use it indirectly rather than on its own.
What's measured
Coverage & cadence
- Time span2021-12-15 → ongoing
- Measured bySuomi-NPP (VIIRS)
- Processing levelLevel 1B
- Spatial extent-180, -90, 180, 90
- FormatsnetCDF
- 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/NPP Moderate Resolution Terrain-Corrected Geolocation L1 6-Min Swath 750m Near Real Time (NRT) product, short-name VNP03MOD_NRT includes the geolocation fields that are calculated for each VIIRS moderate resolution band (M-band) Line of sight (LOS) for all orbits at the nominal resolution of 750 m. The locations and ancillary information correspond to the intersection of the centers of each Field of View (FOV) from 16 detectors in an ideal M-band on the Earth's surface. A digital terrain model is used to model the Earth's surface. The main inputs are the spacecraft attitude and orbit ephemeris data, the instrument telemetry and the digital elevation model. The geolocation fields contained within the VNP03MOD Geolocation files include geodetic latitude, longitude, surface height above the geoid, solar zenith and azimuth angles, satellite zenith and azimuth angles, and a land/water mask for each 750m sample. Additional information is included in the header to enable the calculation of the approximate location of the center of the detectors for any of the VIIRS bands. This product is used as input by subsequent VIIRS Moderate Resolution products, particularly those produced by the Land team.
Get the data
import earthaccess
earthaccess.login(strategy="netrc") # free Earthdata Login
results = earthaccess.search_data(
short_name="VNP03MOD_NRT",
version="2",
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 LANCEMODISBrowsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.