I found the QC flag in the converter pointed to Land_Ocean_Quality_Flag, which is the flag for Dark Target retrieval rather than the DT and DB combined retrievals (AOD_550_Dark_Target_Deep_Blue_Combined).
Instead, AOD_550_Dark_Target_Deep_Blue_Combined_QA_Flag should be used as QC flags.
Also, the QC flags need to be flipped.
Reference link: https://darktarget.gsfc.nasa.gov/products/viirs-modis/level-2-product-contents
I found the QC flag in the converter pointed to
Land_Ocean_Quality_Flag, which is the flag for Dark Target retrieval rather than the DT and DB combined retrievals (AOD_550_Dark_Target_Deep_Blue_Combined).Instead,
AOD_550_Dark_Target_Deep_Blue_Combined_QA_Flagshould be used as QC flags.Also, the QC flags need to be flipped.
Reference link: https://darktarget.gsfc.nasa.gov/products/viirs-modis/level-2-product-contents