The Moderate Resolution Imaging Spectroradiometer (MODIS) MCD43A4 Version 6 Nadir Bidirectional Reflectance Distribution Function (BRDF)-Adjusted Reflectance (NBAR) dataset is produced daily using 16 days of Terra and Aqua MODIS data at 500 meter (m) resolution. The view angle effects are removed from the directional reflectances, resulting in a stable and consistent NBAR product. Data are temporally weighted to the ninth day which is reflected in the Julian date in the file name.
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 MCD43A4 provides NBAR and simplified mandatory quality layers for MODIS bands 1 through 7. Essential quality information provided in the corresponding MCD43A2 data file should be consulted when using this product.
|File Size||~22.1 MB|
|Temporal Extent||2000-02-16 to Present|
|Geographic Dimensions||1200 km x 1200 km|
|Number of Science Dataset (SDS) Layers||14|
|Columns/Rows||2400 x 2400|
|Pixel Size||~500 m|
|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|
|Nadir_Reflectance_Band1||NBAR at local solar noon for Band 1||N/A||16-bit signed integer||32767||N/A||0 to 32766||0.0001|
|Nadir_Reflectance_Band2||NBAR at local solar noon for Band 2||N/A||16-bit signed integer||32767||N/A||0 to 32766||0.0001|
|Nadir_Reflectance_Band3||NBAR at local solar noon for Band 3||N/A||16-bit signed integer||32767||N/A||0 to 32766||0.0001|
|Nadir_Reflectance_Band4||NBAR at local solar noon for Band 4||N/A||16-bit signed integer||32767||N/A||0 to 32766||0.0001|
|Nadir_Reflectance_Band5||NBAR at local solar noon for Band 5||N/A||16-bit signed integer||32767||N/A||0 to 32766||0.0001|
|Nadir_Reflectance_Band6||NBAR at local solar noon for Band 6||N/A||16-bit signed integer||32767||N/A||0 to 32766||0.0001|
|Nadir_Reflectance_Band7||NBAR at local solar noon for Band 7||N/A||16-bit signed integer||32767||N/A||0 to 32766||0.0001|
|0||Processed, good quality (full BRDF inversions)|
|1||Processed, see other QA (magnitude BRDF inversions)|
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 will be implemented in Collection 6.1 reprocessing in 2020.
For complete information about the MCD43A4 known issues refer to the MODIS Land Quality Assessment website.