How to properly mask cloud shadow

machl · by **machl** » Wed Dec 02, 2020 8:51 am America/New_York

Hi,
Everyone, when I processed MODIS-Aqua (such as A2002351 and A2002324), I used the default nlwmin parameter (0.15) in the l2gen step, and then performed l2bin, l3mapgen, the flags used in l3mapgen including LAND,STRAYLIGHT, CLDICE, ATMFAIL, HIGLINT, MODGLINT, HISATZEN, HISOLZEN, LOWLW. But the cloud shadow wasn't masked.
I tried different nlwmin values (0.2,0.3,0.4), but the results did not seem to change, and the cloud shadows were still not masked.
Is there a recommended value of nlwmin? Or my solution is completely wrong? What should I do to mask the cloud shadow correctly?
Thank you very much:smile:

Thunder
attachment 1

attachment 2

b.detracey · by **b.detracey** » Tue Dec 08, 2020 12:06 pm America/New_York

I suspect you will not be able to do this with seadas alone. There are recent publications on this. I am including a link to this paper as an example of such research, not as an endorsement, because I am not an expert. This is just one paper that I happen to remember from the last time I googled this topic, a few years ago.

machl · by **machl** » Tue Dec 22, 2020 6:42 am America/New_York

Thank you, I read the paper you recommended. It is a very wonderful paper, but the method of the paper is complicated to me. Finally, I removed the cloud shadow through visual interpretation.