Question on aerosol retrieval -Sen2core


#22

I did switch off both the Cirrus and BRDF, and again I obtained no changes in the AOT…What is strange is that I made these tests on two separate images/dates, sweeping the same area of course.

But maybe I’ve found something strange in the logs: disrespectful of the VIS_Update_Mode=0 option set in the GIPP file, Sen2Cor outputs this line:

Variable Visibility (aerosol optical thickness)Yes

Indeed, the processor re-calculates the visibility on the map:

Visibility update (based on other dark pixels, Red/NIR bands) = 36.9 km

Taking the initial value, e.g.: Input visibility = 120.0 km
but updating it, as stated on this line, I believe:
Final visibility = 36.9 km (scene average).

I’ve got more or less the same output message on every log that was output on each run of my tests.

The question now is: is it some kind of bug affecting (for some reason) only my Sen2Cor installation, or could it be a more generalized issue?

I will ask a colleague of mine to make a couple of tests with the VIS_Update_Mode option, and will look at his logs. By the way, he’s using the docker version, I installed Sen2Cor via anaconda (we’re both on Linux platform).

Many thanks for any other feedback that could come.


#23

Hi nerissa
MODIS has AOT product of 25km resolution, but I do not know can Sen2Cor build LUT of AOT, anyone help?