MODIS/Aqua Surface Reflectance Daily L2G Global 1km and 500m SIN Grid V006

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.