MCD43A2 v006

MODIS/Terra and Aqua BRDF/Albedo Quality Daily L3 Global 500 m SIN Grid


PI: Crystal Schaaf

Description

The Moderate Resolution Imaging Spectroradiometer (MODIS) MCD43A2 Version 6 Bidirectional Reflectance Distribution Function and Albedo (BRDF/Albedo) Quality dataset is produced daily using 16 days of Terra and Aqua MODIS data at 500 meter (m) resolution. Data are temporally weighted to the ninth day of the 16-day retrieval period which is reflected in the Julian date in the file name. MCD43A2 contains the quality information for the corresponding MCD43A3 Albedo and MCD43A4 Nadir BRDF-Adjusted Reflectance (NBAR) products.

The MCD43A2 contains BRDF/Albedo band quality (inversion information) and days of valid observation within the 16-day period for MODIS bands 1 through 7 along with land water type, snow BRDF albedo, local solar noon, platform, and BRDF/Albedo uncertainty.

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Characteristics

Improvements/Changes from Previous Versions

  • Observations are weighted to estimate the BRDF/Albedo on the ninth day of the 16-day period.
  • MCD43 products use the snow status weighted to the ninth day instead of the majority snow/no-snow observations from the 16-day period.
  • Better quality at high latitudes from use of all available observations for the acquisition period. Collection 5 used only four observations per day.
  • The MCD43 products use L2G-lite surface reflectance as input.
  • When there are insufficient high quality reflectances, a database with archetypal BRDF parameters is used to supplement the observational data and perform a lower quality magnitude inversion. This database is continually updated with the latest full inversion retrieval for each pixel.

Product Maturity

The MODIS BRDF/ALBEDO products have achieved stage 3 validation.

Collection and Granule

Collection

Characteristic Description
CollectionCombined MODIS
DOI10.5067/MODIS/MCD43A2.006
File Size~1 MB
Temporal ResolutionDaily
Temporal Extent2000-02-16 to Present
Spatial ExtentGlobal
Coordinate SystemSinusoidal
DatumN/A
File FormatHDF-EOS
Geographic Dimensions~1200 km x 1200 km

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers19
Columns/Rows2400 x 2400
Pixel Size~500 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
Snow_BRDF_Albedo Snow-free BRDF/Albedo retrieved Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Platform BRDF Albedo Platform information Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_LandWaterType Land Water Type Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_LocalSolarNoon Solar Zenith Angle of Local Solar Noon Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_ValidObs_Band1 Valid Observation for Band 1 N/A 16-bit unsigned integer 0 N/A 1 to 65535 N/A
BRDF_Albedo_ValidObs_Band2 Valid Observation for Band 2 N/A 16-bit unsigned integer 0 N/A 1 to 65535 N/A
BRDF_Albedo_ValidObs_Band3 Valid Observation for Band 3 N/A 16-bit unsigned integer 0 N/A 1 to 65535 N/A
BRDF_Albedo_ValidObs_Band4 Valid Observation for Band 4 N/A 16-bit unsigned integer 0 N/A 1 to 65535 N/A
BRDF_Albedo_ValidObs_Band5 Valid Observation for Band 5 N/A 16-bit unsigned integer 0 N/A 1 to 65535 N/A
BRDF_Albedo_ValidObs_Band6 Valid Observation for Band 6 N/A 16-bit unsigned integer 0 N/A 1 to 65535 N/A
BRDF_Albedo_ValidObs_Band7 Valid Observation for Band 7 N/A 16-bit unsigned integer 0 N/A 1 to 65535 N/A
BRDF_Albedo_Band_Quality_Band1 BRDF Inversion Information for Band 1 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Quality_Band2 BRDF Inversion Information for Band 2 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Quality_Band3 BRDF Inversion Information for Band 3 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Quality_Band4 BRDF Inversion Information for Band 4 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Quality_Band5 BRDF Inversion Information for Band 5 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Quality_Band6 BRDF Inversion Information for Band 6 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Quality_Band7 BRDF Inversion Information for Band 7 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Uncertainty BRDF Albedo Uncertainty N/A 16-bit unsigned integer 32767 N/A 0 to 32766 0.001

Information for the Snow_BRDF_Albedo, BRDF_Albedo_Platform, BRDF_Albedo_LandWatertype, BRDF_Albedo_ValidObs_Band1 through 7, and BRDF_Albedo_Band_Quality_Band1 through 7 legends are available in the MCD43A2 File Specification.

Known Issues

The metadata information within the HDF file of the Version 6 MCD43A2 gives incorrect SDS layer parameters for BRDF_Albedo_ValidObs_Band1 through 7. The metadata states that the Valid Range is 0 to 32767 with a scaling factor of 0.001, which is incorrect. The Data Layers Characteristics section of this product page is accurate, the correct Valid Range is 0 to 65535 with no scaling factor.

For complete information about the MCD43A2 known issues refer to the MODIS Land Quality Assessment website.

Documentation

Using the Data

Tools

Citation

DOI: 10.5067/MODIS/MCD43A2.006

About the Image

Combined MODIS BRDF Albedo Valid Observations 1-4-3 data from the MCD43A2 product over western United States June 7, 2018.

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