Earthdata Forum

I have a question about the MOD35 product, more specifically the Cloud Flag - 3.9-11 μm test. How can I find out if the test was performed and therefore the result is 0, or because low clouds were detected?
In the MODIS Cloud Mask User's Guide, in Table 3 (Bit Description of MODIS Cloud Mask Quality Assurance SDS), I did not find this test, but only the 3.7-11μm test.

The aim of my analysis is to investigate the occurrence of low clouds, for which I would first like to filter out the low clouds.

An answer would be very helpful.
Many thanks in advance.

With kind regards
Samira

Dear Samira Zander:
Yes, you are looking at the right table/values, but most likely at an old document.
The most recent QA documentation (https://atmosphere-imager.gsfc.nasa.gov/sites/default/files/ModAtmo/documents/QA_Plan_C61_Master_2021_09_22.pdf) correctly reports the 3.9-11um test in the table at page 37-39.
Additionally, the 3.7um channel is not used to perform any test in the MOD35 code, so it is safe to assume 3.9um wherever the documentation mentions 3.7um.