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Description

The MOD09GA Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the MOD09GA Version 6.1 data product.

The MOD09GA Version 6 product provides an estimate of the surface spectral reflectance of Terra 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 kilometer (km) observation bands and geolocation flags. The reflectance layers from the MOD09GA are used as the source data for many of the MODIS land products.

Known Issues

  • Striping due to a dead detector is noticeable for bands 5, 6, and 7 in scenes acquired February 24 through October 31, 2000. Corrections were implemented to reduce the striping in data acquired after November 1, 2000. Users should always check the band quality for dead detectors even though reflectance values may be in the valid range.
  • The Collection 6 MODIS Land Surface Reflectance product (MOD09) 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 provides 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.

Version Description

The MOD09GA Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the MOD09GA Version 6.1 data product (https://doi.org/10.5067/MODIS/MOD09GA.061).

Product Summary

Platforms
Terra
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
2000-02-24 to 2023-02-17
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
C2763297184-LPCLOUD
Data State
DEPRECATED
Processing Level
2G
Published
Updated
Science Keywords
Reflectance

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). MOD09GA MODIS/Terra 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/MOD09GA.006 Date Accessed: 2025-11-02

File Naming Convention

MOD09GA.A2002281.h33v11.006.2015151071841.hdf

The file name begins with the Product Short Name (MOD09GA) followed by the Julian Date of Acquisition formatted as AYYYYDDD (A2002281), the Tile Identifier which is horizontal tile and vertical tile provided as hXXvYY (h33v11), the Version of the data collection (006), the Julian Date and Time of Production designated as YYYYDDDHHMMSS (2015151071841), and the Data Format (hdf).

Documents

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Publications Citing This Dataset

Filters
Title Year Author
WaterSmart-GIS—A web application of a data assimilation model to support irrigation research and decision making Zhao, H.
Mapping the northern limit of double cropping using a phenology-based algorithm and Google Earth Engine Guo, Y.
The extreme heat wave over western North America in 2021—An assessment by means of land surface temperature Cotlier, G. I.
Daily monitoring of marine mucilage using the MODIS products—A case study of 2021 mucilage bloom in the Sea of Marmara, Turkey Yagci, A. L.
Environmental factors driving evapotranspiration over a grassland in a transitional climate zone in China Zhang, L.
A neural network-based method for satellite-based mapping of sediment-laden sea ice in the Arctic Waga, H.
Improving dengue forecasts by using geospatial big data analysis in Google Earth Engine and the historical dengue information-aided long short term memory modeling Li, Z.
Reconstruction of daily evapotranspiration under cloudy sky constrained by soil water budget balance Jiang, Y.
Deep learning-based spatiotemporal data fusion using a patch-to-pixel mapping strategy and model comparisons Ao, Z.
Mapping snow cover in forests using optical remote sensing, machine learning and time-lapse photography Luo, J.
SHOWING 10 OF 122

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
gflags_1 Geolocation flags Bit Field uint8 255 255 to 248 N/A
granule_pnt_1 Granule pointer N/A uint8 255 255 to 254 N/A
iobs_res_1 Observation number N/A uint8 255 255 to 254 N/A
num_observations_1km Number of observations within a  pixel N/A int8 -1 -1 to 127 N/A
num_observations_500m Number of observations per 500m pixel N/A int8 -1 -1 to 127 N/A
obscov_500m_1 Observation coverage Percent int8 -1 -1 to 100 0.01
orbit_pnt_1 Orbit pointer N/A int8 -1 -1 to 15 N/A
QC_500m_1 Surface Reflectance 500m Quality Assurance Bit Field uint32 787410671 787410671 to 4294966019 N/A
q_scan_1 250m scan value information N/A uint8 255 255 to 254 N/A
Range_1 Distance to sensor Meters uint16 0 0 to 65535 25
SensorAzimuth_1 Azimuth angle to sensor Degree int16 -32767 -32767 to 18000 0.01
SensorZenith_1 Zenith angle to sensor Degree int16 -32767 -32767 to 18000 0.01
SolarAzimuth_1 Azimuth angle to sun Degree int16 -32767 -32767 to 18000 0.01
SolarZenith_1 Zenith angle to sun Degree int16 -32767 -32767 to 18000 0.01
state_1km_1 1km Reflectance Data State QA Bit Field uint16 65535 65535 to 57335 N/A
sur_refl_b01_1 Surface Reflectance for Band 1 N/A int16 -28672 -28672 to 16000 0.0001
sur_refl_b02_1 Surface Reflectance for Band 2 N/A int16 -28672 -28672 to 16000 0.0001
sur_refl_b03_1 Surface Reflectance for Band 3 N/A int16 -28672 -28672 to 16000 0.0001
sur_refl_b04_1 Surface Reflectance for Band 4 N/A int16 -28672 -28672 to 16000 0.0001
sur_refl_b05_1 Surface Reflectance for Band 5 N/A int16 -28672 -28672 to 16000 0.0001
sur_refl_b06_1 Surface Reflectance for Band 6 N/A int16 -28672 -28672 to 16000 0.0001
sur_refl_b07_1 Surface Reflectance for Band 7 N/A int16 -28672 -28672 to 16000 0.0001
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