I applied the tutorial for 'Sentinel-2 Cloud Masking with s2cloudless' and have this script in GEE:


In this tutorial, I do not understand the purpose of 'cloud transform' layer and I do not know how to display the final cloud free image. Should I apply a median to see the final result? If yes, over which layer?


The purpose of 'cloud transform' is to estimate projection of cloud shadows based on cloud position and sun azimuth. Or, as the author specifies it // Project shadows from clouds for the distance specified by the CLD_PRJ_DIST input.

Then, if you want to display the cloud-free image, you need to apply all those masks using apply_cld_shdw_mask() function. Here is a result: https://code.earthengine.google.com/0701d40fb1f844cfd376e8e6cbd7d946

However, if you want to make a cloud-free composite, you have to map this function over many images and then reduce them into a composite (e.g. take median). Here is a result: https://code.earthengine.google.com/d9aaa276f0fa1ab33e78230e8f348c6f

  • Thanks @Basile, this solved my problem. I was after the composite as you mentioned – Paris Apr 30 at 13:48

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