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The Visible Infrared Imaging Radiometer Suite (VIIRS) is aboard the joint NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) and NOAA-platforms. VIIRS collects visible and infrared imagery along with global observations of Earth's land, atmosphere, cryosphere, and ocean. 

VIIRS extends observational records collected by similar instruments aboard previously-launched satellites, such as NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) and NOAA's Advanced Very High Resolution Radiometer (AVHRR). VIIRS snow cover and sea ice algorithms are specifically designed for compatibility with MODIS snow cover and sea ice datasets, which ensures continuity between MODIS and VIIRS data products and supports comparison of snow and sea ice data over the lives of MODIS, VIIRS, and beyond to facilitate long-term climate data records.

VIIRS Filenames

VIIRS filenames for Level 2G, Level 3, and Level 4 products follow a naming convention which provides useful information regarding the specific product.

In this example for a swath product, the filename VJ121.A2021101.0054.002.2021102014936.nc indicates:

  • VJ121: Product Short Name
  • .A2021101: Acquisition year and Julian day (AYYYYDDD)
  • .0054: Coordinated Universal Time (HHMM)
  • .002: Collection Version
  • .2021102014936: Production year, Julian day, and time (YYYYDDDHHMMSS)
  • .nc: Data Format (NetCDF4)

In this example for a tiled product, the filename VNP09GA.A2019004.h15v05.002.2020244220120.h5 indicates:

  • VNP09GA: Product Short Name
  • .A2019004: Acquisition year and Julian day (AYYYYDDD)
  • .h15v05: Tile Identifier (horizontalXXverticalYY) (see VIIRS Tiling System below)
  • .002: Collection Version
  • .2020244220120: Production year, Julian day, and time (YYYYDDDHHMMSS)
  • .h5: Data Format (HDF-EOS5)

In this example for a Climate Modeling Grid (CMG) product, the filename VNP09CMG.A2019009.002.2021148200733.h5 indicates:

  • VNP09CMG: Product Short Name
  • .A2019009: Acquisition year and Julian day (AYYYYDDD)
  • .002: Collection Version
  • .2021148200733: Production year, Julian day, and time (YYYYDDDHHMMSS)
  • .h5: Data Format (HDF-EOS5)

VIIRS Product Long Name

A VIIRS product long name contains information about the data including the sensor, satellite, collection name and more. One example of a VIIRS Product Long Name is VIIRS/NPP Surface Reflectance 8-Day L3 Global 500m SIN Grid V001. Note that both Version 1 and Version 2 follow the same long name format and only the version number (i.e. V001) will change (i.e. V002).

For example, all products belonging to the VIIRS/NPP Surface Reflectance 8-Day L3 Global 500m SIN Grid V001 collection have the following characteristics:

  • VIIRS/NPP: Instrument/Satellite
  • Surface Reflectance: Geophysical Parameter
  • 8-Day: Temporal Resolution
  • L3: Processing Level
  • Global: Global Coverage
  • 500m: Spatial Resolution
  • SIN Grid: Sinusoidal Grid
  • V001: Collection Version

For example, all products belonging to the VIIRS/JPSS1 Land Surface Temperature and Emissivity 6-Min L2 Swath 750m V002 collection have the following characteristics:

  • VIIRS/JPSS1: Instrument/Satellite
  • Land Surface Temperature and Emissivity: Geophysical Parameter
  • 6-Min: Temporal Resolution
  • L2: Processing Level
  • Swath: Swath Coverage
  • 750m: Spatial Resolution
  • V002: Collection Version

VIIRS Sinusoidal Tile Grid

The VIIRS tiling system is the same as the MODIS tiling system.

A tile grid overlays an image of Earth, with 460 non-fill tiles covering the globe.

Level 2G, Level 3, and Level 4 Suomi NPP NASA VIIRS land products use this Sinusoidal grid tiling system. Tiles are 10 degrees by 10 degrees at the equator. The tile coordinate system starts at (0,0) (horizontal tile number, vertical tile number) in the upper left corner and proceeds right (horizontal) and downward (vertical). The tile in the bottom right corner is (35,17).

VIIRS Climate Modeling Grid (CMG)

The VIIRS CMG is the same as the MODIS CMG. The CMG datasets provide global coverage in a Geographic Latitude and Longitude projection at a resolution of 0.05 degrees. The geographic coordinates of the upper left corner of the upper left pixel of a VIIRS CMG image are -180.00 degrees longitude, 90.00 degrees latitude. The geographic coordinates of the lower right corner of the lower right pixel are 180.00 degrees longitude, -90.00 degrees latitude.

Imagery of Earth

The VIIRS data distributed by LP DAAC are available at the following levels:

  • Level 2: derived geophysical variables at the same resolution and location as Level 1 source data (swath products)
  • Level 2G: Level 2 data mapped on a uniform space-time grid scale (Sinusoidal)
  • Level 3: gridded variables in derived spatial and/or temporal resolutions
  • Level 4: model output or results from analyses of lower-level data

VIIRS products have two sources of metadata: the embedded HDF-EOS5 metadata, and the external Earth Observing System Data and Information System (EOSDIS) metadata, known as the EOSDIS Core System (ECS) metadata. The HDF-EOS5 metadata contains valuable information including global attributes and dataset specific attributes pertaining to the granule. An external metadata file is provided in XML format (.xml) and is provided along with the VIIRS product. This file provides a subset of the HDF-EOS5 metadata. Some key features of VIIRS HDF-EOS5 metadata attributes may include the following:

  • The Xdim and Ydim represent the rows and columns of the data, respectively.
  • The Projection and ProjParams identify the projection and its corresponding projection parameters.
  • The Sinusoidal Projection is used for most of the gridded VIIRS land products and has a unique sphere measuring 6371007.181 meters.
  • The UpperLeftPointMtrs is in projection coordinates and identifies the very upper left corner of the upper left pixel of the image data.
  • The LowerRightMtrs identifies the very lower right corner of the lower right pixel of the image data. These projection coordinates are the only metadata that accurately reflect the extreme corners of the gridded image.
  • Coordinate fields named EastBoundingCoord, WestBoundingCoord, NorthBoundingCoord, and SouthBoundingCoord represent the latitude and longitude coordinates of the geographic tile corresponding to the data.

The dataset attributes contain specific Science Dataset (SDS) information such as the data range and applicable scaling factors for the data. Information for each NASA VIIRS land data product can be found on the respective dataset landing pages.

Learn more about VIIRS

Instrument Type

Spectrometers/Radiometers

Instrument Subtype

Imaging Spectrometers/Radiometers

Specifications

Resolution

Spatial

375 m, 750 m

Spectral

22 spectral bands ranging in wavelength from 0.402 µm to 12.49 µm

Temporal

Daily

Platforms

Frequently Asked Questions

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