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Description

The Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Vegetation Indices 16-Day (MYD13A1) Version 6.1 product provides Vegetation Index (VI) values at a per pixel basis at 500 meter (m) spatial resolution. There are two primary vegetation layers. The first is the Normalized Difference Vegetation Index (NDVI), which is referred to as the continuity index to the existing National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer (NOAA-AVHRR) derived NDVI. The second vegetation layer is the Enhanced Vegetation Index (EVI), which has improved sensitivity over high biomass regions. The algorithm for this product chooses the best available pixel value from all the acquisitions from the 16 day period. The criteria used is low clouds, low view angle, and the highest NDVI/EVI value.

Provided along with the vegetation layers and two quality assurance (QA) layers are reflectance bands 1 (red), 2 (near-infrared), 3 (blue), and 7 (mid-infrared), as well as four observation layers.

Known Issues

Version Description

The following changes and improvements were implemented for inputs to MODIS Version 6.1 vegetation indices data products: (1) Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 – 2017, and (2) A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).

Product Summary

Platforms
Aqua
Instruments
MODIS
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Spatial Resolution
500 Meters x 500 Meters
Spatial Reference System(s)
MODIS Sinusoidal Tiling System
Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2002-07-04 to Present
Temporal Resolution
16 Day
Data Partner
Land Processes Distributed Active Archive Center (LP DAAC) ,
MODIS Adaptive Processing System, Terrestrial Information Systems Laboratory, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/MODAPS)
Concept ID
C2565794046-LPCLOUD
Data State
ACTIVE
Number of Files/Granules
157732
Processing Level
3
Published
Updated
Science Keywords
Vegetation Index ,
Normalized Difference Vegetation Index (NDVI)

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Didan, K. (2021). MODIS/Aqua Vegetation Indices 16-Day L3 Global 500m SIN Grid V061 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MODIS/MYD13A1.061 Date Accessed: 2026-02-13

File Naming Convention

MYD13A1.A2025201.h23v10.061.2025217235526.hdf

The file name begins with the Product Short Name (MYD13A1) followed by the Julian Date of Acquisition formatted as AYYYYDDD (A2025201), the Tile Identifier which is horizontal tile and vertical tile provided as hXXvYY (h23v10), the Version of the data collection (061), the Julian Date and Time of Production designated as YYYYDDDHHMMSS (2025217235526), and the Data Format (hdf).

Documents

USER'S GUIDE

ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)

PRODUCT QUALITY ASSESSMENT

SCIENCE DATA PRODUCT VALIDATION

GENERAL DOCUMENTATION

Publications Citing This Dataset

Filters
Title Year Author
Effects of climate change, coal mining and grazing on vegetation dynamics in the mountain permafrost regions Qi, X.-l.
Land surface phenology retrievals for arid and semi-arid ecosystems Xie, Q.
Behind the scenes of streamflow model performance Bouaziz, L. J. E.
Optimized approach for developing soil fugitive dust emission inventory in “2+26” Chinese cities Li, T.
Long-term changes of surface albedo and vegetation indices in north of Iran Sabziparvar, A. A.
Integrating eddy fluxes and remote sensing products in a rotational grazing native tallgrass prairie pasture Wagle, P.
EVI time-series breakpoint detection using convolutional networks for online deforestation monitoring in Chaco forest Grings, F.
Detecting changes in understorey and canopy vegetation cycles in West Central Alberta using a fusion of Landsat and MODIS McClelland, C. J. R.
A robust method for reconstructing global MODIS EVI time series on the Google Earth Engine Kong, D.
Assessing the vegetation condition of Herat Province, Afghanistan using GIS Razipoor, M.E.
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Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
500m 16 days blue reflectance Surface Reflectance Band 3 N/A int16 -1000 0 to 10000 0.0001
500m 16 days composite day of the year Day of year VI pixel Julian day int16 -1 1 to 366 N/A
500m 16 days EVI 500m 16 days EVI EVI int16 -3000 -2000 to 10000 0.0001
500m 16 days MIR reflectance Surface Reflectance Band 7 N/A int16 -1000 0 to 10000 0.0001
500m 16 days NDVI 500m 16 days NDVI NDVI int16 -3000 -2000 to 10000 0.0001
500m 16 days NIR reflectance Surface Reflectance Band 2 N/A int16 -1000 0 to 10000 0.0001
500m 16 days pixel reliability Quality reliability of VI pixel Rank int8 -1 0 to 3 N/A
500m 16 days red reflectance Surface Reflectance Band 1 N/A int16 -1000 0 to 10000 0.0001
500m 16 days relative azimuth angle Relative azimuth angle of VI pixel Degree int16 -4000 -18000 to 18000 0.01
500m 16 days sun zenith angle Sun zenith angle of VI pixel Degree int16 -10000 0 to 18000 0.01
500m 16 days view zenith angle View zenith angle of VI Pixel Degree int16 -10000 0 to 18000 0.01
500m 16 days VI Quality VI quality indicators Bit Field uint16 65535 0 to 65534 N/A
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