VNP09H1 v001

VIIRS/NPP Surface Reflectance 8-Day L3 Global 500 m SIN Grid

PI: Eric Vermote

Historic reprocessing is underway for VIIRS Version 2 (Collection 2) data products. Due to Version 2 reprocessing of the historical time series, latency for VIIRS Version 1 data products has varied.


The 8-day Visible Infrared Imaging Radiometer Suite (VIIRS) Surface Reflectance (VNP09H1) Version 1 composite product provides an estimate of land surface reflectance from the NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) VIIRS sensor for three imagery bands (I1, I2, I3) at nominal 500 meter resolution (~463 meter). The 500 meter dataset is derived through resampling the native 375 meter VIIRS resolution in the L2 input product. The data are corrected for atmospheric conditions such as the effects of molecular gases, including ozone and water vapor, and for the effects of atmospheric aerosols. Each pixel represents the best possible Level 2G observation during an 8-day period, which is selected on the basis of high observation coverage, low sensor angle, the absence of clouds or cloud shadow, and aerosol loading. The three reflectance bands, this product includes a state quality assurance (QA) layer and a reflectance band quality layer.

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Product Maturity

Validation at stage 3 has been achieved for the VIIRS surface reflectance product suite. Visit VIIRS Land Product Quality Assessment Product Maturity for information on product maturity status.

Collection and Granule


Characteristic Description
CollectionSuomi NPP VIIRS
File Size~26 MB
Temporal ResolutionMulti-Day
Temporal Extent2012-01-17 to Present
Spatial ExtentGlobal
Coordinate SystemSinusoidal
File FormatHDF-EOS5
Geographic Dimensions1200 km x 1200 km


Characteristic Description
Number of Science Dataset (SDS) Layers5
Columns/Rows2400 x 2400
Pixel Size500 m

Layers / Variables

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
SurfReflect_I1 500 m Surface Reflectance Band I1 N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
SurfReflect_I2 500 m Surface Reflectance Band I2 N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
SurfReflect_I3 500 m Surface Reflectance Band I3 N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
SurfReflect_State_500m Surface Reflectance State Quality Assurance (QA) Bit Field 16-bit unsigned integer 65535 N/A 0 to 13311 N/A
SurfReflect_QC_500m Surface Reflectance Band Quality Control (QC) Bit Field 16-bit unsigned integer 65535 N/A 0 to 32767 N/A

Product Quality

The bit field mappings for QC and State QA layers are provided in Section 3.3 Tables 17 and 19 of the User Guide.

The Quality Control (QC) and State QA layers are stored in an efficient bit-encoded manner. The unpack_sds_bits executable from the LDOPE Tools is available to the user community to help parse and interpret the quality layer.

Quality assurance information should be considered when determining the usability of data for a particular science application. The ArcGIS MODIS-VIIRS Python Toolbox contains tools capable of decoding quality data layers while producing thematic quality raster files for each quality attribute.

In addition to data access and transformation processes, AppEEARS also has the capability to unpack and interpret the quality layers.

The following metadata related changes have been made to the User Guide:

  • Valid Range of 0 to 13311 for the SurfReflect_State_500m layer (Table 8).
  • Description of Bits 10-11 in the SurfReflect_State_500m layer changed from “Internal cloud algorithm flag” and “Internal fire algorithm flag” changed to "Spare (Unused)" (Table 19).
  • Bits 2-3 “Cloud State” in the SurfReflect_QC_500m layer set to 11 redirects users to utilize Bits 0-1 “Cloud State” in the SurfReflect_State_500m layer (Table 17).

The following changes have been implemented in the data:

  • Fill Value for Surface Reflectance Bands changed from 0 to -28672 for forward processing as of May 25, 2017.
  • Fill Value for the SurfReflect_QC_500m layer set to reflect 65535 for forward processing as of August 21, 2017.
  • Bit 12 “Atmospheric Correction Performed” in the SurfReflect_QC_500m layer set to "Yes" for forward processing as of August 21, 2017.

The VNP09 User Guide V1.1 remains available for data processed prior to August 2017.

For complete information about product quality, refer to the VIIRS Land Product Quality Assessment website.

Known Issues

The VIIRS Land Surface Reflectance product (VNP09) may incorrectly flag retrievals as ‘High Aerosol’ over brighter surfaces and at higher view angles. This will impact the downstream VIIRS BRDF/Albedo (VNP43) and Vegetation Index (VNP13) data products which use the aerosol quantity flag to screen out high aerosol values.

Corrections will be implemented in Collection 2 reprocessing in 2022.

For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website and in Section 4.0 “Caveats and Known Problems” of the User Guide.

About the image

The VNP09H1 surface reflectance band I3-I2-I1 data over the western United States, August 30 - September 6, 2018.

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User Guide V 1.1
User Guide V 1.7
Algorithm Theoretical Basis Document (ATBD)

Using the Data

Access Data


DOI: 10.5067/VIIRS/VNP09H1.001