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Description

The MYD09GA Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the MYD09GA Version 6.1 data product.

The MYD09GA Version 6 product provides an estimate of the surface spectral reflectance of Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Bands 1 through 7, corrected for atmospheric conditions such as gasses, aerosols, and Rayleigh scattering. Provided along with the 500 meter (m) surface reflectance, observation, and quality bands are a set of ten 1 km observation bands and geolocation flags. The reflectance layers from the MYD09GA are used as the source data for many of the MODIS land products.

Known Issues

  • The Collection 6 MODIS Land Surface Reflectance product (MYD09) may incorrectly flag retrievals as ‘High Aerosol’ over brighter surfaces and at higher view angles. This will impact the downstream MODIS BRDF/Albedo (MCD43) and Vegetation Index (MOD13 and MYD13) data products which use the aerosol quantity flag to screen out high aerosol values.
  • Corrections were implemented in Collection 6.1 reprocessing.
  • For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.

Improvements/Changes from Previous Versions

  • Improvements to the aerosol retrieval and correction algorithm along with new aerosol retrieval look-up tables.
  • Refinements to the internal snow, cloud, and cloud shadow detection algorithms. Uses Bidirectional Reflectance Distribution Function (BRDF) database to better constrain the different threshold used.
  • Processes ocean bands to create a new Surface Reflectance Ocean product and provide Quality Assurance (QA) datasets for these bands.
  • Improved discrimination of salt pans from cloud and snow, along with the inclusion of a salt pan flag in the QA band.

Product Summary

Platforms
Aqua
Instruments
MODIS
Spatial Extent
N: 90 S: -90 E: 180 W: -180
Spatial Resolution
500 Meters x 500 Meters
Geographic Region
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2002-07-04 to 2023-02-26
Temporal Resolution
1 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
c2763370201-lpcloud
Data State
DEPRECATED
Processing Level
2G
Published
Updated

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

Vermote, E., & Wolfe, R. (2015). MYD09GA MODIS/Aqua Surface Reflectance Daily L2G Global 1kmand 500m SIN Grid V006 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MODIS/MYD09GA.006 Date Accessed: 2025-06-25

Data Center Citation

Eric Vermote, Robert Wolfe. 2015. MODIS/Aqua Surface Reflectance Daily L2G Global 1km and 500m SIN Grid V006. Sioux Falls, South Dakota, USA: NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MODIS/MYD09GA.006.

Documents

ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD) The ATBD provides physical theory and mathematical procedures for the calculations used to produce the data products.
GENERAL DOCUMENTATION The File Specification provides a description of the product file including Scientific Data Sets and their attributes.
PRODUCT QUALITY ASSESSMENT The LDOPE Land Product Quality Assessment website provides known issues, maneuvers, and product quality of the land products.
USER'S GUIDE The technical information in the User's Guide enables users to interpret and use the data products.

Learning Resources

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