MCD43C4 v006

MODIS/Terra and Aqua BRDF/Albedo Nadir BRDF-Adjusted Reflectance Daily L3 Global 0.05 Deg CMG


PI: Crystal Schaaf

Description

The Moderate Resolution Imaging Spectroradiometer (MODIS) MCD43C4 Version 6 Bidirectional Reflectance Distribution Function and Albedo (BRDF/Albedo) Nadir BRDF-Adjusted Reflectance (NBAR) dataset is produced daily using 16 days of Terra and Aqua MODIS data in a 0.05 degree (5,600 meters at the equator) Climate Modeling Grid (CMG). Data are temporally weighted to the ninth day of the retrieval period which is reflected in the Julian date in the file name. This CMG product covers the entire globe for use in climate simulation models.

MCD43C4 removes view angle effects from directional reflectances to model the values as if they were collected from a nadir view at local solar noon. These NBAR values are calculated from MCD43C1. The product includes separate NBAR layers for MODIS spectral bands 1 through 7 as well as ancillary layers for quality, local solar noon, percent finer resolution inputs, snow cover, and uncertainty.

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.
  • CMG Albedo is estimated using all the clear-sky observations within the 1,000 m grid for MCD43C 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/MCD43C4.006
File Size~90 MB
Temporal ResolutionDaily
Temporal Extent2000-02-16 to Present
Spatial ExtentGlobal
Coordinate SystemGeographic Latitude and Longitude
DatumN/A
File FormatHDF-EOS
Geographic DimensionsGlobal

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers12
Columns/Rows7200 x 3600
Pixel Size5600 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor Additional Offset
Nadir_Reflectance_Band1 Nadir reflectance for MODIS band 1 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001 N/A
Nadir_Reflectance_Band2 Nadir reflectance for MODIS band 2 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001 N/A
Nadir_Reflectance_Band3 Nadir reflectance for MODIS band 3 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001 N/A
Nadir_Reflectance_Band4 Nadir reflectance for MODIS band 4 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001 N/A
Nadir_Reflectance_Band5 Nadir reflectance for MODIS band 5 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001 N/A
Nadir_Reflectance_Band6 Nadir reflectance for MODIS band 6 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001 N/A
Nadir_Reflectance_Band7 Nadir reflectance for MODIS band 7 N/A 16-bit signed integer 32767 N/A 0 to 32766 0.001 N/A
BRDF_Quality Global albedo quality N/A 8-bit unsigned integer 255 N/A 0 to 254 N/A N/A
Local_Solar_Noon Local solar noon zenith angle Degree 8-bit unsigned integer 255 N/A 0 to 90 N/A N/A
Percent_Inputs Processed finer resolution data that contributed to this CMG pixel Percent 8-bit unsigned integer 255 N/A 0 to 100 N/A N/A
Percent_Snow Underlying data flagged as snow Percent 8-bit unsigned integer 255 N/A 0 to 100 N/A N/A
BRDF_Albedo_Uncertainty BRDF inversion information N/A 16-bit unsigned integer 32767 N/A 0 to 32766 0.001 N/A

Quality bit index

Value Description
0 Best quality, 100% with full inversions
1 Good quality, 75% or more with best full inversions and 90% or more with full inversions
2 Relative good quality, 75% or more with full inversions
3 Mixed, 75% or less full inversions and 25% or less fill values
4 All magnitude inversions or 50% or less fill values
5 50% or more fill values
255 Fill Value

Known Issues

For complete information about the MCD43C4 known issues refer to the MODIS Land Quality Assessment website.

Documentation

Using the Data

Tools

Citation

DOI: 10.5067/MODIS/MCD43C4.006

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