Several of NASA's distributed active archive centers (DAACs) archive VIIRS data, and each has its own naming conventions. Details for each DAAC are included below.

LP DAAC

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)

In this example for a combined VIIRS/NPP+JPSS1 product, the filename VCD19A1CMG.A2021240.002.2025188150851.h5 indicates:

• VCD19A1CMG: Product Short Name
• .A2021240: Acquisition year and Julian day (AYYYYDDD)
• .002: Collection Version
• .2025188150851: 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: Instruments/Satellites
• Land Surface Temperature and Emissivity: Geophysical Parameter
• 6-Min: Temporal Resolution
• L2: Processing Level
• Swath: Swath Coverage
• 750m: Spatial Resolution
• V002: Collection Version

For example, all products belonging to the combined VIIRS/NPP+JPSS1 BRDF Model Parameters Daily L3 Global 750m RSIN Grid V002 collection have the following characteristics:

• VIIRS/NPP+JPSS1: Instrument/Satellite
• BRDF Model Parameters: Geophysical Parameter
• Daily: Temporal Resolution
• L3: Processing Level
• Global: Global Coverage
• 500m: Spatial Resolution
• RSIN Grid: Rotated Sinusoidal Grid
• V002: Collection Version

VIIRS Sinusoidal Tile Grid

The VIIRS Sinusoidal Tile Grid that applies to most VIIRS products is the same as the MODIS Sinusoidal Tile Grid. Please see below for information about the tiling system for VIIRS MAIAC specific products.

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 Zonal Sinusoidal Projection (ZSP)

The Global Sinusoidal Projection has significant spatial distortions off the Greenwich meridian and towards the poles. These distortions are mitigated in the Zonal Sinusoidal Projection (ZSP), which was originally named as Rotated Sinusoidal (RSIN) projection. Each of the four zones has the standard Sinusoidal projection rotated 90°. This projection retains an equal area property, reduces geographic distortions, and can be easily re-projected to any standard projection without loss of information. It also keeps the same total number of pixels by filling in the significant empty space in the global Sinusoidal projection. There is a certain overlap between tiles towards the poles. The user can select the tile providing minimal distortion as the one with the shortest distance from its center to the pixel. 

The MAIAC global grid tiling system divides Earth's surface into 648 tiles arranged in a 36 × 18 grid, with each tile covering 1,200 × 1,200 km². Tile coordinates begin at (0, 0) in the upper-left corner, with horizontal tile numbers (0–35) increasing eastward and vertical tile numbers (0–17) increasing southward. Tiles are grouped into four horizontal zones based on their center meridians: Zone 0 (tiles 0–8, centered at 20°E), Zone 1 (tiles 9–17, centered at 110°E), Zone 2 (tiles 18–26, centered at 160°W), and Zone 3 (tiles 27–35, centered at 70°W). A list of the corner coordinates are provided for every tile within the Zonal Sinusoidal Projection.

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.

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.