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Description

The Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Vegetation Indices 16-Day (MYD13C1) Version 6.1 product provides a Vegetation Index (VI) value at a per pixel basis. 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 Climate Modeling Grid (CMG) consists 3,600 rows and 7,200 columns of 5,600 meter (m) pixels. Global MYD13C1 data are cloud-free spatial composites of the gridded 16-day 1 kilometer MYD13A2 data, and are provided as a Level 3 product projected on a 0.05 degree (5,600 m) geographic CMG. The MYD13C1 has data fields for NDVI, EVI, VI QA, reflectance data, angular information, and spatial statistics such as mean, standard deviation, and number of used input pixels at the 0.05 degree CMG resolution.

Known Issues

Improvments/Changes from Previous Version

  • The 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.
  • A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).

Version Description

Collection Version 6.1 Processing and Reprocessing

Product Summary

Platforms
Aqua
Instruments
MODIS
Spatial Extent
N: 90 S: -90 E: 180 W: -180
Spatial Resolution
5600 Meters x 5600 Meters
Geographic Region
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
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
C2565794051-LPCLOUD
Data State
ACTIVE
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 0.05Deg CMG V061 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MODIS/MYD13C1.061 Date Accessed: 2025-10-25

File Naming Convention

MYD13C1.A2025201.061.2025218051732.hdf

The file name begins with the Product Short Name (MYD13C1) followed by the Julian Date of Acquisition formatted as AYYYYDDD (A2025201), the Version of the data collection (061), the Julian Date and Time of Production designated as YYYYDDDHHMMSS (2025218051732), 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

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
CMG 0.05 Deg 16 days #1km pix +-30deg VZ Number of 1km pixels used with VZ angle less than + or - 30 degs Number uint8 255 255 to 36 N/A
CMG 0.05 Deg 16 days Avg sun zen angle View zenith angle of VI Pixel Degree int16 -10000 -10000 to 9000 0.01
CMG 0.05 Deg 16 days blue reflectance Surface Reflectance Band 3 N/A int16 -1000 -1000 to 10000 0.0001
CMG 0.05 Deg 16 days EVI 16 day EVI EVI int16 -3000 -3000 to 10000 0.0001
CMG 0.05 Deg 16 days EVI std dev Standard deviation computed from input EVI pixels EVI int16 -3000 -3000 to 10000 0.0001
CMG 0.05 Deg 16 days MIR reflectance Surface Reflectance Band 7 N/A int16 -1000 -1000 to 10000 0.0001
CMG 0.05 Deg 16 days NDVI 16 day NDVI NDVI int16 -3000 -3000 to 10000 0.0001
CMG 0.05 Deg 16 days NDVI std dev Standard deviation computed from input NDVI pixels NDVI int16 -3000 -3000 to 10000 0.0001
CMG 0.05 Deg 16 days NIR reflectance Surface Reflectance Band 2 N/A int16 -1000 -1000 to 10000 0.0001
CMG 0.05 Deg 16 days number of 1km pix used Number of 1 km input pixels used Number uint8 255 255 to 36 N/A
CMG 0.05 Deg 16 days pixel reliabilty Quality reliability of VI pixel Rank int8 -1 -1 to 4 N/A
CMG 0.05 Deg 16 days red reflectance Surface Reflectance Band 1 N/A int16 -1000 -1000 to 10000 0.0001
CMG 0.05 Deg 16 days VI Quality VI quality indicators Bit Field uint16 65535 65535 to 65534 N/A
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