Quality (QA) flags are an indicator of the algorithm team’s assessment of the quality of the data.  QA flag values range from 0 – 3 where 0 is lowest quality. We advise using only highest quality data (QA=3) for land products.  For ocean products we advise using anything above QA zero.  In collection 6 data this information is included in the SDS “Land_Ocean_Quality_Flag”.

In collection 5 data the QA flags are embedded in the SDS “Quality_Assurance_Land” and “Quality_Assurance_Ocean.”  The QA values must be read and interpreted from these SDS parameters.

MODIS aerosol products can be generated on the LADSWEB site with only recommended quality data.

This can be accomplished as follows:

After selecting data from your search put in in the shopping cart.

Select “View Your Shopping Cart”.  At the bottom of the page select “Post process and order data”  Click “Order”.  On the next page select “Data Quality Screening Service (DQSS).  Click “Order”.  The default values on the next page will be the QA values of data which we recommend for users.  Click “Order” to order your data.