Combined MODIS Valid Observation for band 7 data from the MCD43D39 product across the globe, August 2, 2018.View full-size image
The MCD43D39 Version 6 Bidirectional Reflectance Distribution Function and Albedo (BRDF/Albedo) QA ValidObs Band 7 dataset is produced daily using 16 days of Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data at 30 arc second (1,000 meter (m)) resolution. Data are temporally weighted to the ninth day which is reflected in the Julian date in the file name. This Climate Modeling Grid (CMG) product covers the entire globe for use in climate simulation models. Due to the large file size, MCD43D product contains just one data layer. MCD43D39 provides MODIS band 7 valid observation quality information for the MCD43D products.
MCD43D39 contains the valid observation quality layer representing each of the 16 days of the retrieval period for MODIS band 7.
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.
|File Size||~160.5 MB|
|Temporal Extent||2000-02-16 to Present|
|Coordinate System||Geographic Latitude and Longitude|
|Number of Science Dataset (SDS) Layers||1|
|Columns/Rows||43200 x 21600|
|Pixel Size||~1000 m|
|SDS Name||Description||Units||Data Type||Fill Value||No Data Value||Valid Range||Scale Factor|
|Global_BRDF_ValidObs_Band7||Valid Observation for band 7||Bit Field||16-bit unsigned integer||0||N/A||1 to 65535||N/A|
|0||Observation not used|
|1||Valid clear observation|
The quality layer is stored in an efficient bit-encoded manner. The unpack_sds_bits executable from the LDOPE Tools is available to the user community to help parse and interpret this layer.
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 MCD43D39 known issues refer to the MODIS Land Quality Assessment website.