VNP13C2 v001

VIIRS/NPP Vegetation Indices Monthly L3 Global 0.05 Deg CMG


PI: Kamel Didan

Description

The Suomi National Polar-Orbiting Partnership (S-NPP) NASA Visible Infrared Imaging Radiometer Suite (VIIRS) Vegetation Indices (VNP13C2) Version 1 data product provides vegetation indices by a process of selecting the best available pixel over a monthly acquisition period at 0.05 degree (Deg) resolution. The VNP13 data products are designed after the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua Vegetation Indices product suite to promote the continuity of the Earth Observation System (EOS) mission.

The VNP13 algorithm process produces three vegetation indices: The Normalized Difference Vegetation Index (NDVI), the Enhanced Vegetation Index (EVI), and the Enhanced Vegetation Index-2 (EVI2). NDVI is one of the longest continual remotely sensed time series observations, using both the red and near-infrared (NIR) bands. EVI is a slightly different vegetation index that is more sensitive to canopy cover, while NDVI is more sensitive to chlorophyll. EVI2 is a reformation of the standard 3-band EVI, using the red band and NIR band. This reformation addresses arising issues when comparing VIIRS EVI to other EVI models that do not include a blue band. EVI2 will eventually become the standard EVI.

Along with the three Vegetation Indices layers, this product also includes layers for the standard deviations of each Vegetation Index; NIR reflectance; three shortwave infrared (SWIR) reflectance; red, blue, and green reflectance; number of pixels, number of pixels used; pixel reliability; average sun angle, and a quality layer. Two low resolution browse images are also available for each VNP13C2 product: EVI and NDVI.

Characteristics

Product Maturity

Validation at stage 1 has been achieved for the VIIRS Vegetation Index (VI) product suite. Visit VIIRS Land Product Quality Assessment Product Maturity for information on product maturity status.

Collection and Granule

Collection

Characteristic Description
CollectionS-NPP VIIRS
DOI10.5067/VIIRS/VNP13C2.001
File Size~150 MB
Temporal ResolutionMulti-Day
Temporal Extent2012-01-01 to Present
Spatial ExtentGlobal
Coordinate SystemGeographic Latitude and Longitude
DatumN/A
File FormatHDF-EOS5
Geographic DimensionsGlobal

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers18
Columns/Rows7200 x 3600
Pixel Size0.05 Degrees

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor Additional Offset
CMG 0.05 Deg monthly #1km pix +-30deg VZ Number of 1 kilometer pixels within 30° of the view zenith angle Number 8-bit unsigned integer 255 N/A 0 to 36 N/A N/A
CMG 0.05 Deg monthly #1km pix used Number of 1 km pixels used for monthly 0.05° (5,600 m) composite Number 8-bit unsigned integer 255 N/A 0 to 36 N/A N/A
CMG 0.05 Deg monthly Avg sun zen angle Average sun zenith angle for each pixel Degree 16-bit signed integer -20000 N/A 0 to 18000 100 N/A
CMG 0.05 Deg monthly EVI 3 band Enhanced Vegetation Index EVI 16-bit signed integer -15000 to -12000 N/A -10000 to 10000 10000 N/A
CMG 0.05 Deg monthly EVI std dev Standard Deviation for the 3 band Enhanced Vegetation Index EVI 16-bit signed integer -15000 to -12000 N/A 0 to 10000 10000 N/A
CMG 0.05 Deg monthly EVI2 2 band Enhanced Vegetation Index EVI 16-bit signed integer -15000 to -12000 N/A -10000 to 10000 10000 N/A
CMG 0.05 Deg monthly EVI2 std dev Standard Deviation for the 2 band Enhanced Vegetation Index EVI2 16-bit signed integer -15000 to -12000 N/A 0 to 10000 10000 N/A
CMG 0.05 Deg monthly NDVI Normalized Difference Vegetation Index NDVI 16-bit signed integer -15000 to -12000 N/A -10000 to 10000 10000 N/A
CMG 0.05 Deg monthly NDVI std dev Standard Deviation for the Normalized Difference Vegetation Index NDVI 16-bit signed integer -15000 to -12000 N/A 0 to 10000 10000 N/A
CMG 0.05 Deg monthly NIR reflectance Near-infrared Radiation reflectance (846–885 nm) N/A 16-bit signed integer -1000 N/A 0 to 10000 10000 N/A
CMG 0.05 Deg monthly SWIR1 reflectance Shortwave Infrared Radiation reflectance (1230–1250 nm) N/A 16-bit signed integer -1000 N/A 0 to 10000 10000 N/A
CMG 0.05 Deg monthly SWIR2 reflectance Shortwave Infrared Radiation reflectance (1580–1640 nm) N/A 16-bit signed integer -1000 N/A 0 to 10000 10000 N/A
CMG 0.05 Deg monthly SWIR3 reflectance Shortwave Infrared Radiation reflectance (2225–2275 nm) N/A 16-bit signed integer -1000 N/A 0 to 10000 10000 N/A
CMG 0.05 Deg monthly VI Quality Bit field that assigns each pixel a Quality Assessment (QA) attribute Bit Field 16-bit unsigned integer 65535 N/A 0 to 65534 N/A N/A
CMG 0.05 Deg monthly blue reflectance Blue band reflectance (478–498 nm) N/A 16-bit signed integer -1000 N/A 0 to 10000 10000 N/A
CMG 0.05 Deg monthly green reflectance Green band reflectance (545–565 nm) N/A 16-bit signed integer -1000 N/A 0 to 10000 10000 N/A
CMG 0.05 Deg monthly pixel reliability Pixel usefulness using a simple rank class Rank 8-bit signed integer -4 to -1 N/A 0 to 11 N/A N/A
CMG 0.05 Deg monthly red reflectance Red band reflectance (600–680 nm) N/A 16-bit signed integer -1000 N/A 0 to 10000 10000 N/A

¹All scale factors for VNP13 products are to be divided.

Fill Values for the Vegetation Index Layers

Fill Value Description
-15000 over ocean/water
-14000 over Antarctica
-13000 over land
-12000 over high latitude during dark winter

Fill Values for the Pixel Reliability Layer

Fill Value Description
-4 over ocean/water
-3 over Antarctica
-2 over high latitude during dark winter
-1 over land

Product Quality

Product Quality information can be found in the combined User Guide and Algorithm Theoretical Basis Document (ATBD). For the “CMG 0.05 Deg monthly pixel reliability” SDS Layer, a rank quality table for each pixel can be found in Table 5 on page 35. For the “CMG 0.05 Deg monthly VI Quality” SDS Layer, for use with all VI’s, a bit field Quality Assurance table can be found in Table 13 on pages 43-44 with additional information available in Table 25 on page 60. Accuracy Precision and Uncertainty information is available on page 65.

Known Issues

Known issues are described here.

Documentation

Using the Data

E-Learning

Land Ho! Exploring Earth’s Land Surface with Suomi NPP NASA VIIRS Land Data

Tools

Citation

DOI: 10.5067/VIIRS/VNP13C2.001

About the Image