Problems obtaining reflectance from radiance using iCOR OLCI on SNAP

I’m attempting to atmospherically correct a series of Sentinel-3 OLCI EFR images using the iCOR-SENTINEL-3-OLCI plugin on SNAP, and am struggling with the plugin.

For information: I am using SNAP 9.0.0 and version 3.0.0 of the iCOR plugin. I’m on a Windows computer, I’m unsure what the RAM is but as it’s a university computer I have been assured that it’s certainly sufficient for my processing needs. If more information is needed I can provide it.

Ultimately, what I would like to obtain is a version of my L1 scene which has been atmospherically corrected (to account for water vapour/aerosol effect), with the bands in reflectance - NOT radiance. This should be ready for my next stage which is further processing on ArcGIS.

When I run my scene through the iCOR plugin, I find that the output is atmospherically corrected but not converted into reflectance. Rather, the bands are all still radiance.

To get around this, I have tried several things:

  1. I have tried to process my L1 scene first by using the radiance-to-reflectance function, and then attempting to use the iCOR plugin on this radtoref version of my scene. This does not work - I don’t even receive an error message, it just refuses to run.
  2. I also run the iCOR plugin on my original L1 scene, providing me with an output which I then wanted to open on SNAP so as to try apply the radiance-to-reflectance tool on that. However, there’s no xfdumanifest file in this radtoref product, which means I can’t/don’t know how to open it in SNAP to see whether I can then run the iCOR plugin on this.

I’ve been unable to find a solution on here/more broadly to help. If anyone would be able to help me I’d be very grateful. Please also let me know if there’s any more information I could provide to help this be resolved. Also for reference: this is my first time doing any atmospheric correction. Until now I’ve only ever used L2 data. So apologies if any of this comes across amateurish, I really want to learn.



Thanks for your question. I’m sorry to hear that you have issue with iCOR.
The iCOR team is not regularly visiting this forum.
So, it might be better to ask VITO directly: Contact Us | VITO Remote Sensing

However, till now I haven’t heard that the results of iCOR are still radiances.
At least it wasn’t reported in earlier posts in this forum.
But I think VITO can help you.