Cloud shadow detection problem

Optical Toolbox
1

Hello,
I face a problem with cloud shadows detection using quality_scene_classification in ESA SNAP during L2A products analysis.

  1. The opaque cloud shadows could have a lot of gaps and sometimes smaller than the actual shadow.
  2. The thin cirrus shadows are not detected at all.

cloudshadow
cloudshadow2536×1166 722 KB
thincirrus
thincirrus1267×1177 632 KB

The products used in the illustrations above:

  1. S2B_MSIL2A_20180505T094029_N0207_R036_T35VLF_20180505T115132.SAFE
  2. S2A_MSIL2A_20180530T094031_N0208_R036_T35VME_20180530T122531.SAFE

When can we wait for updates in the cloud shadow classification? What can be done to improve cloud shadow detection?
Thanks.

With all best,
Marharyta

2

Dear Marharyta,

as alternative for detecting clouds and cloud shadows in Sentinel-2 MSI images you can try the ‘fmask’ algorithm implemented in Python:

http://pythonfmask.org

Federico

1 Like
3

Another alternative is IdePix for Sentinel-2.
You can find it in the menu of SNAP at Optical / Pre-processing /Masking / IdePix / Sentinel-2 MSI.
But most cloud detection algorithms have their pros and cons. You just need to find the one which serves your needs best,

1 Like