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l2gen gas_opt question

Posted: Tue Apr 09, 2019 6:29 pm America/New_York
by alaroy
Good evening SeaDAS'ers :)

I'm wondering - when using l2gen, what is the difference between gas_opt=8 (noted as "H2O" in the usage message) and gas_opt=16 (noted as "use atrem (H2O)" in the usage message)?

Thank you in advance for your help!

-Andrew L.

l2gen gas_opt question

Posted: Tue Apr 09, 2019 6:57 pm America/New_York
by OB.DAAC - SeanBailey
The way the gas correction is applied.   If gas_opt=16, an implementation of ATREM is used.  It is intended only for hyperspectral sensors with bands that can include significant gaseous absorption - particularly water vapor.  Most sensors supported by l2gen do not require (or can even make use of) this option.

Sean

l2gen gas_opt question

Posted: Wed Apr 10, 2019 11:01 am America/New_York
by alaroy
Thank you, Sean, for the quick response!

I'm guessing MODISA's 841-876 nm band is not one that can can benefit / use ATREM.

l2gen gas_opt question

Posted: Wed Apr 10, 2019 12:12 pm America/New_York
by OB.DAAC - SeanBailey
yep...