Global NDVI from the VJ113C1 product over Brazil during July 2023.
View full-size imageThe NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Vegetation Indices (VJ113C1) Version 2 data product provides vegetation indices by a process of selecting the best available pixel over a 16-day acquisition period at 0.05 degree 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 VJ113 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 VJ113C1 product: EVI and NDVI.
More details can be found in this VIIRS Land V2 Changes document.
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.
Characteristic | Description |
---|---|
Collection | NOAA-20 VIIRS |
DOI | 10.5067/VIIRS/VJ113C1.002 |
File Size | ~159 MB |
Temporal Resolution | Monthly |
Temporal Extent | 2018-01-01 to Present |
Spatial Extent | Global |
Coordinate System | Geographic Latitude and Longitude |
Datum | N/A |
File Format | HDF-EOS5 |
Geographic Dimensions | Global |
Characteristic | Description |
---|---|
Number of Science Dataset (SDS) Layers | 18 |
Columns/Rows | 7200 x 3600 |
Pixel Size | 5600 m |
SDS Name | Description | Units | Data Type | Fill Value | No Data Value | Valid Range | Scale Factor |
---|---|---|---|---|---|---|---|
CMG 0.05 Deg 16 days #1km pix +-30deg VZ | CMG 0.05 Deg 16 days #1km pix +-30deg VZ | Number | 8-bit unsigned integer | 255 | N/A | 0 to 36 | N/A |
CMG 0.05 Deg 16 days #1km pix used | CMG 0.05 Deg 16 days #1km pix used | Number | 8-bit unsigned integer | 255 | N/A | 0 to 36 | N/A |
CMG 0.05 Deg 16 days Avg sun zen angle | CMG 0.05 Deg 16 days Avg sun zen angle | Degree | 16-bit signed integer | -20000 | N/A | 0 to 18000 | 100 |
CMG 0.05 Deg 16 days EVI | CMG 0.05 Deg 16 days EVI | EVI | 16-bit signed integer | -15000, -14000, -13000, -12000 | N/A | -10000 to 10000 | 10000 |
CMG 0.05 Deg 16 days EVI std dev | CMG 0.05 Deg 16 days EVI std dev | EVI | 16-bit signed integer | -15000 | N/A | 0 to 10000 | 10000 |
CMG 0.05 Deg 16 days EVI2 | CMG 0.05 Deg 16 days EVI2 | EVI2 | 16-bit signed integer | -15000, -14000, -13000, -12000 | N/A | -10000 to 10000 | 10000 |
CMG 0.05 Deg 16 days EVI2 std dev | CMG 0.05 Deg 16 days EVI2 std dev | EVI2 | 16-bit signed integer | -15000 | N/A | 0 to 10000 | 10000 |
CMG 0.05 Deg 16 days NDVI | CMG 0.05 Deg 16 days NDVI | NDVI | 16-bit signed integer | -15000, -14000, -13000, -12000 | N/A | -10000 to 10000 | 10000 |
CMG 0.05 Deg 16 days NDVI std dev | CMG 0.05 Deg 16 days NDVI std dev | NDVI | 16-bit signed integer | -15000 | N/A | 0 to 10000 | 10000 |
CMG 0.05 Deg 16 days NIR reflectance | CMG 0.05 Deg 16 days NIR reflectance (846–885 nm) | N/A | 16-bit signed integer | -1000 | N/A | 0 to 10000 | 10000 |
CMG 0.05 Deg 16 days SWIR1 reflectance | CMG 0.05 Deg 16 days SWIR1 reflectance (1230–1250 nm) | N/A | 16-bit signed integer | -1000 | N/A | 0 to 10000 | 10000 |
CMG 0.05 Deg 16 days SWIR2 reflectance | CMG 0.05 Deg 16 days SWIR2 reflectance (1580–1640 nm) | N/A | 16-bit signed integer | -1000 | N/A | 0 to 10000 | 10000 |
CMG 0.05 Deg 16 days SWIR3 reflectance | CMG 0.05 Deg 16 days SWIR3 reflectance (2225–2275 nm) | N/A | 16-bit signed integer | -1000 | N/A | 0 to 10000 | 10000 |
CMG 0.05 Deg 16 days VI Quality | CMG 0.05 Deg 16 days VI Quality | Bit Field | 16-bit unsigned integer | 65535 | N/A | 0 to 65534 | N/A |
CMG 0.05 Deg 16 days blue reflectance | CMG 0.05 Deg 16 days blue reflectance (478–498 nm) | N/A | 16-bit signed integer | -1000 | N/A | 0 to 10000 | 10000 |
CMG 0.05 Deg 16 days green reflectance | CMG 0.05 Deg 16 days green reflectance (545–565 nm) | N/A | 16-bit signed integer | -1000 | N/A | 0 to 10000 | 10000 |
CMG 0.05 Deg 16 days pixel reliability | CMG 0.05 Deg 16 days pixel reliability | Rank | 8-bit signed integer | -4 to -1 | N/A | 0 to 11 | N/A |
CMG 0.05 Deg 16 days red reflectance | CMG 0.05 Deg 16 days red reflectance (600–680 nm) | N/A | 16-bit signed integer | -1000 | N/A | 0 to 10000 | 10000 |
All scale factors are to be divided.
Fill Value | Description |
---|---|
-15000 | over ocean/water |
-14000 | over Antarctica |
-13000 | over land |
-12000 | over high latitude during the dark winter |
Fill Value | Description |
---|---|
-4 | over ocean/water |
-3 | over Antarctica |
-2 | over high latitude during the dark winter |
-1 | over land |
Rank | Description |
---|---|
0 | Excellent |
1 | Good |
2 | Acceptable |
3 | Marginal |
4 | Pass |
5 | Questionable |
6 | Poor |
7 | Cloud Shadow |
8 | Snow/Ice |
9 | Cloud |
10 | Estimated |
11 | LTAVG |
Product Quality information can be found in the combined User Guide and Algorithm Theoretical Basis Document (ATBD). For the “CMG 0.05 Deg 16 days pixel reliability” SDS Layer, a rank quality table for each pixel can be found in Table 5. For the “CMG 0.05 Deg 16 days VI Quality” SDS Layer, for use with all VI’s, a bit field Quality Assurance table can be found in Table 13, with additional information available in Tables 22 and 23. Accuracy Precision and Uncertainty information is available in Section 12.1.4.
The Quality Assessment (QA) layer is 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.
For additional information on product quality, refer to the VIIRS Land Product Quality website.
Due to missing critical inputs, this product lacks coverage for tiles h33v07 and h18v14, which are located over water.
For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website and the User Guide and ATBD.