MCD43GF v006

MODIS/TERRA+Aqua BRDF/Albedo Gap-Filled Snow-Free Daily L3 Global 30ArcSec CMG


PI: Crystal Schaaf

Description

The Daily Moderate Resolution Imaging Spectroradiometer (MODIS) (Bidirectional Reflectance Distribution Function and Albedo (BRDF/Albedo) 30 arc second, Global Gap-Filled, Snow-Free, (MCD43GF) Version 6 is derived from the 30 arc second Climate Modeling Grid (CMG) MCD43D Version 6 product suite, with additional processing to provide a gap-filled, snow-free product. The highest quality full inversion values were used for the temporal fitting effort and supplemented with lower quality pixels, spatial fitting, and spatial smoothing as needed. The status of each pixel can be found in the quality layer for each band. To generate a snow-free product, pixels with ephemeral snow were removed using the MCD43D41 snow flags. The underlying MCD43D utilizes a BRDF model derived from all available high quality cloud clear reflectance data over a 16 day moving window centered on and emphasizing the daily day of interest (the ninth day of each retrieval period as reflected in the Julian date in the filename). This 30 arc second BRDF model is then used to produce the Albedo and NBAR products (MCD43D). These BRDF model parameters are computed for MODIS spectral bands 1 through 7 (0.47 um, 0.55 um, 0.67 um, 0.86 um, 1.24 um, 1.64 um, 2.1 um), as well as the shortwave infrared band (0.3-5.0 um), visible band (0.3-0.7 um), and near-infrared (0.7-5.0 um) broad bands.

The MCD43GF product includes 67 layers containing black-sky albedo (BSA) at local solar noon, isotropic model parameter (ISO), volumetric model parameter (VOL), geometric model parameter (GEO), quality (QA), Nadir BRDF-Adjusted Reflectance (NBAR) at local solar noon, and white-sky albedo (WSA). Due to the large file size, each data layer is distributed as a separate HDF file. Users are encouraged to download the quality layers for each of the 10 bands to check quality assessment information before using the BRDF/Albedo data.

The MCD43 product is not recommended for solar zenith angles beyond 70 degrees.

Version 6.1 reprocessing will begin in the fall of 2019. In the reprocessing, the QA values for the MCD43GF product will change to reflect the band 5 and 6 dead detector issues.

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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.
  • In cases where insufficient high-quality reflectances are obtained, 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.
  • CMG Albedo is estimated using all the clear-sky observations within the 1,000 m grid as opposed to aggregating from the 500 m albedo.

Product Maturity

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

Collection and Granule

Collection

Characteristic Description
CollectionCombined MODIS
DOI10.5067/MODIS/MCD43GF.006
File Size~224 MB
Temporal ResolutionDaily
Temporal Extent2000-03-03 to Present
Spatial ExtentGlobal
Coordinate SystemGeographic Latitude and Longitude
DatumN/A
File FormatHDF-EOS
Geographic DimensionsGlobal

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers67
Columns/Rows43200 x 21600
Pixel Size~1000 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
Albedo_Map_0.659 (BSA) Black-Sky Albedo band 1 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.858 (BSA) Black-Sky Albedo band 2 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.47 (BSA) Black-Sky Albedo band 3 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.555 (BSA) Black-Sky Albedo band 4 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_1.24 (BSA) Black-Sky Albedo band 5 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_1.64 (BSA) Black-Sky Albedo band 6 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_2.13 (BSA) Black-Sky Albedo band 7 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.7-5.0 (BSA) Black-Sky Albedo NIR N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.3-5.0 (BSA) Black-Sky Albedo shortwave broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.3-0.7 (BSA) Black-Sky Albedo visual broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.659 (GEO) BRDF Albedo geometric weight for band 1 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.858 (GEO) BRDF Albedo geometric weight for band 2 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.47 (GEO) BRDF Albedo geometric weight for band 3 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.555 (GEO) BRDF Albedo geometric weight for band 4 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_1.24 (GEO) BRDF Albedo geometric weight for band 5 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_1.64 (GEO) BRDF Albedo geometric weight for band 6 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_2.13 (GEO) BRDF Albedo geometric weight for band 7 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.7-5.0 (GEO) BRDF Albedo geometric weight for NIR broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.3-5.0 (GEO) BRDF Albedo geometric weight for shortwave broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.3-0.7 (GEO) BRDF Albedo geometric weight for vis broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.659 (ISO) BRDF Albedo isotropic weight for band 1 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.858 (ISO) BRDF Albedo isotropic weight for band 2 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.47 (ISO) BRDF Albedo isotropic weight for band 3 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.555 (ISO) BRDF Albedo isotropic weight for band 4 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_1.24 (ISO) BRDF Albedo isotropic weight for band 5 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_1.64 (ISO) BRDF Albedo isotropic weight for band 6 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_2.13 (ISO) BRDF Albedo isotropic weight for band 7 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.7-5.0 (ISO) BRDF Albedo isotropic weight for NIR broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.3-5.0 (ISO) BRDF Albedo isotropic weight for shortwave broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.3-0.7 (ISO) BRDF Albedo isotropic weight for vis broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.659 (NBAR) NBAR band 1 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001
Albedo_Map_0.858 (NBAR) NBAR band 2 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001
Albedo_Map_0.47 (NBAR) NBAR band 3 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001
Albedo_Map_0.555 (NBAR) NBAR band 4 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001
Albedo_Map_1.24 (NBAR) NBAR band 5 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001
Albedo_Map_1.64 (NBAR) NBAR band 6 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001
Albedo_Map_2.13 (NBAR) NBAR band 7 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001
QA_Albedo_Map_0.659 BRDF/Albedo quality for MODIS band 1 N/A 8-bit unsigned integer 255 N/A 0 to 7 N/A
QA_Albedo_Map_0.858 BRDF/Albedo quality for MODIS band 2 N/A 8-bit unsigned integer 255 N/A 0 to 7 N/A
QA_Albedo_Map_0.47 BRDF/Albedo quality for MODIS band 3 N/A 8-bit unsigned integer 255 N/A 0 to 7 N/A
QA_Albedo_Map_0.555 BRDF/Albedo quality for MODIS band 4 N/A 8-bit unsigned integer 255 N/A 0 to 7 N/A
QA_Albedo_Map_1.24 BRDF/Albedo quality for MODIS band 5 N/A 8-bit unsigned integer 255 N/A 0 to 7 N/A
QA_Albedo_Map_1.64 BRDF/Albedo quality for MODIS band 6 N/A 8-bit unsigned integer 255 N/A 0 to 7 N/A
QA_Albedo_Map_2.13 BRDF/Albedo quality for MODIS band 7 N/A 8-bit unsigned integer 255 N/A 0 to 7 N/A
QA_Albedo_Map_0.7-5.0 BRDF/Albedo quality for MODIS NIR broadband N/A 8-bit unsigned integer 255 N/A 0 to 7 N/A
QA_Albedo_Map_0.3-5.0 BRDF/Albedo quality for MODIS shortwave broadband N/A 8-bit unsigned integer 255 N/A 0 to 7 N/A
QA_Albedo_Map_0.3-0.7 BRDF/Albedo quality for MODIS vis broadband N/A 8-bit unsigned integer 255 N/A 0 to 7 N/A
Albedo_Map_0.659 (VOL) BRDF Albedo volumetric weight for band 1 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.858 (VOL) BRDF Albedo volumetric weight for band 2 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.47 (VOL) BRDF Albedo volumetric weight for band 3 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.555 (VOL) BRDF Albedo volumetric weight for band 4 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_1.24 (VOL) BRDF Albedo volumetric weight for band 5 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_1.64 (VOL) BRDF Albedo volumetric weight for band 6 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_2.13 (VOL) BRDF Albedo volumetric weight for band 7 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.7-5.0 (VOL) BRDF Albedo volumetric weight for NIR broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.3-5.0 (VOL) BRDF Albedo volumetric weight for shortwave broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.3-0.7 (VOL) BRDF Albedo volumetric weight for vis broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.659 (WSA) White-Sky Albedo band 1 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.858 (WSA) White-Sky Albedo band 2 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.47 (WSA) White-Sky Albedo band 3 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.555 (WSA) White-Sky Albedo band 4 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_1.24 (WSA) White-Sky Albedo band 5 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_1.64 (WSA) White-Sky Albedo band 6 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_2.13 (WSA) White-Sky Albedo band 7 N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.7-5.0 (WSA) White-Sky Albedo near infrared broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.3-5.0 (WSA) White-Sky Albedo near shortwave broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_Map_0.3-0.7 (WSA) White-Sky Albedo visual broadband N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001

BRDF/Albedo Band Quality Description

Value Description
0 Best quality, full inversion (Weight of Determination (WoDs), Root Mean Square Error (RMSE) majority good)
1 Good quality, full inversion
2 Magnitude Inversion (number of observations >= 7)
3 Magnitude Inversion (number of observations >= 2 & < 7
4 Temporal fit
5 Spatial fit
6 Spatial smoothing
7 Solar Zenith Angle extension

Known Issues

There is an error in the DataFieldName value in the metadata. This affects bands 2-7 for the years 2000-2004 and 2013.

For complete information about MCD43D01 known issues refer to the MODIS Land Quality Assessment website.

Documentation

Using the Data

Access Data

Citation

DOI: 10.5067/MODIS/MCD43GF.006

About the Image

Combined MODIS white-sky albedo band 1 data from the MCD43GF product across the globe, July 8, 2017.

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