How to do AC for downloaded S3-OLCI L1 data?

I’m new to SNAP and OLCI data. I want to do Atmospheric Correction for OLCI L1 data.
First, I used “Radiance-to-Reflectance Processor” to convert TOA radiance to TOA reflectance. It worked.
Second, I used “IdePix” to do Cloud Screening. But it failed.
Then, I changed my way. I tried to use “C2RCC” directly do AC on the downloaded OLCI L1 data. Result files were written successfully! But I don’t know if my operation was correct or not. Is it true to directly use “C2RCC” to do AC on the L1 data(TOA radiance)?
Another question, can we apply “C2RCC” to clear water (not coastal or inland water, for example, open-sea ware)regions?
(the L1 data I used were downloade from Sentinel Open Access Hub, Reduce Resolution, ended with “MAR_O_NT_002”)

Thanks in advance.


Yes, you can use the C2RCC directly on the L1 data. But it does the AC only over water. It can’t do it over land.
The algorithm should also work on open-water. But the results are always very region dependent. For several regions, it works good, for some others not so good. You have to judge the results for your area.

If you still want to do cloud screening, you should run IdePix on the L1 TOA radiances data.

Thanks very much!

Your reply helped a lot!

Is there any other tools to do AC for open-water for SNAP? It should be globally operational to do AC for open-water. The most difficult thing is to do AC for Case-2 water. As far as I see, the AC for open-water should be more accurate and more mature...

No, there are not many ACs for OLCI available yet. You can also try the Level2 product from Eumetsat. But probably you already did.

Thanks a lot

Hi, Did there any tools like Sen2Cor did the atmospheric correction for Sentinel-3 landarea, I want to fusion with S2 &S3. Thankyou !