MCD43A1 v006

MODIS/Terra+Aqua BRDF/Albedo Model Parameters Daily L3 Global 500 m SIN Grid


PI: Crystal Schaaf

The MCD43A1 Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the MCD43A1 Version 6.1 data product.

Description

The Moderate Resolution Imaging Spectroradiometer (MODIS) MCD43A1 Version 6 Bidirectional Reflectance Distribution Function and Albedo (BRDF/Albedo) Model Parameters 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 retrieval period which is reflected in the Julian date in the file name. MCD43A1 provides the three model weighting parameters (isotropic, volumetric, and geometric) used to derive the Albedo (MCD43A3) and Nadir BRDF-Adjusted Reflectance (NBAR) (MCD43A4) products.

Users are urged to use the band specific quality flags to isolate the highest quality full inversion results for their own science applications as described in the User Guide.

The MCD43A1 provides the three model weighting parameters for MODIS spectral bands 1 through 7 as well as the visible, near infrared (NIR), and shortwave bands. Along with the three-dimensional parameter layers for these bands are the simplified mandatory quality layers for each of the 10 bands. Essential quality information provided in the corresponding MCD43A2 data file should be consulted when using this product.

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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

Validation at stage 3 has been achieved for all MODIS BRDF/Albedo products. Further details regarding MODIS land product validation for the MCD43 data products are available from the MODIS Land Team Validation site.

Collection and Granule

Collection

Characteristic Description
CollectionCombined MODIS
DOI10.5067/MODIS/MCD43A1.006
File Size~54.88 MB
Temporal ResolutionDaily
Temporal Extent2000-02-16 to 2023-02-17
Spatial ExtentGlobal
Coordinate SystemSinusoidal
DatumN/A
File FormatHDF-EOS
Geographic Dimensions~1200 km x 1200 km

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers20
Columns/Rows2400 x 2400
Pixel Size500 m

Layers / Variables

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
BRDF_Albedo_Band_Mandatory_Quality_Band1 BRDF Albedo Mandatory Quality for Band 1 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Mandatory_Quality_Band2 BRDF Albedo Mandatory Quality for Band 2 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Mandatory_Quality_Band3 BRDF Albedo Mandatory Quality for Band 3 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Mandatory_Quality_Band4 BRDF Albedo Mandatory Quality for Band 4 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Mandatory_Quality_Band5 BRDF Albedo Mandatory Quality for Band 5 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Mandatory_Quality_Band6 BRDF Albedo Mandatory Quality for Band 6 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Mandatory_Quality_Band7 BRDF Albedo Mandatory Quality for Band 7 Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Mandatory_Quality_vis BRDF Albedo Mandatory Quality for vis broadband Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Mandatory_Quality_nir BRDF Albedo Mandatory Quality for NIR broadband Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Band_Mandatory_Quality_shortwave BRDF Albedo Mandatory Quality for shortwave broadband Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A
BRDF_Albedo_Parameters_Band1 3D Parameter (iso, vol, geo) for Band 1 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001
BRDF_Albedo_Parameters_Band2 3D Parameter (iso, vol, geo) for Band 2 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001
BRDF_Albedo_Parameters_Band3 3D Parameter (iso, vol, geo) for Band 3 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001
BRDF_Albedo_Parameters_Band4 3D Parameter (iso, vol, geo) for Band 4 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001
BRDF_Albedo_Parameters_Band5 3D Parameter (iso, vol, geo) for Band 5 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001
BRDF_Albedo_Parameters_Band6 3D Parameter (iso, vol, geo) for Band 6 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001
BRDF_Albedo_Parameters_Band7 3D Parameter (iso, vol, geo) for Band 7 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001
BRDF_Albedo_Parameters_vis 3D Parameter (iso, vol, geo) for vis broadband N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001
BRDF_Albedo_Parameters_nir 3D Parameter (iso, vol, geo) for NIR broadband N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001
BRDF_Albedo_Parameters_shortwave 3D Parameter (iso, vol, geo) for shortwave broadband N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001

Mandatory Quality bit index

Value Description
0 Processed, good quality (full BRDF inversions)
1 Processed, see other QA (magnitude BRDF inversions)
2 Processed, good quality (full BRDF inversions), Band 6 is fill value due to non-functional or noisy detectors
3 Processed, see other QA (magnitude BRDF inversions), Band 6 is fill due to non-functional or noisy detectors
255 Fill Value

Known Issues

The incorrect representation of the aerosol quantities (low average high) in the C6 MYD09 and MOD09 surface reflectance products may have impacted downstream products particularly over arid bright surfaces. This (and a few other issues) have been corrected for C6.1. Therefore users should avoid substantive use of the C6 MCD43 products and wait for the C6.1 products. In any event, users are always strongly encouraged to download and use the extensive QA data provided in MCD43A2, in addition to the briefer mandatory QAs provided as part of the MCD43A1, 3, and 4 products.

Corrections were implemented in Collection 6.1 reprocessing.

For complete information about the MCD43A1 known issues refer to the MODIS Land Quality Assessment website.


About the image

Combined MODIS BRDF Albedo Parameters 1-4-3 data from the MCD43A1 product over western United States June 7, 2018.

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Documentation

User Guide
Algorithm Theoretical Basis Document (ATBD)
File Specification

Using the Data

Access Data

Citation

DOI: 10.5067/MODIS/MCD43A1.006