Idepix operator vs Idepix in graph

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#1

Hi,

I am using the IDEPIX algorithm to create a cloud mask in a S3 OLCI image. When I use the operator individually (optical -> preprocessing -> masking -> …) the output product contains the different masks produced by IDEPIX:

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However, when I combine it with other operators in a graph like this:

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The output does not contain the masks. The Oa*_reflectance only contains (as expected) the TOA reflectance bands

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Am I missing something or is this an error?
M

#2

This is an error. The workaround is fortunately easy: Simply connect the output from BandMaths first to BandMerge, then the Idepix. When you view the graph, in the BandMerge node the BandMaths should be listed as first product, the Idepix as second. The masks should be included now when you run the graph.

1 Like
#3

Thanks, good to know

M

#4

Another realated question, after applying the graph succesfuly and keeping the masks produced by IDEPEIX, I need to mosaic two S3 OLCI images. Using the mosaic operator does not preserve the masks.

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Is this again an error with a work around solution?

M

#5

This is not really an error. Masks simply are not copied.

#6

Any known way to preserve them after mosaic?

M

#7

In case someone is looking for the same, the solution is to convert the mask into a regular mask using BandMath. After this, you can mosaic the product and keep the masks produced by IDEPIX

M

#8

Also, the mask data is still available in the pixel_classif_flags band. You can create masks from these via the MaskManager.