S3-OLCI C2RCC geocorrection

Hello everyone, I encountered a problem when using snap software for the first time.

Does C2RCC do geometric correction when processing sentinel-3 data? If not, how to use SNAP to geometrically correct sentinel-3 data?

After using the C2RCC plug-in for chlorophyll concentration inversion, I found that place should be wrong place.

How should I solve it, help is greatly appreciated!

The C2RCC does not change the geo-location. If you see the displacement afterwards it should also be visible in the source.
The accuracy of the Sentinel-3 OLCI geo-location depends on which data is used for the geo-locations. OLCI provides two. The tie-points give only good approximation. Often this is sufficient and when processing data (e.g. reprojection) it is faster. The other data set provides orthorectified geo-location for each pixel.
You can switch between both in the options:


Sorry that i did not understand very well , is that mean if I want to run C2rcc for S3 OLCI, by select this option " Read sentinel-3 OLCI products with per-pixel geo -coding instead of using tie-points", this will make reprojection to the C2rcc output.


This option will not reproject the data to another CRS, like UTM.
But the values are more accurate. Because each pixel has assigned a specific lat/lon value.
Also, the geo-locations are orthorectified. This means that the location is corrected for the elevation.
More details in the help:

The difference is often not very big, and it depends on your use-case if the accuracy is important.
Using the pixel-based geo-locations slows down some processing steps like the reprojection to another CRS.

Hi Marpet

Thanks a lot for all support.

Yes i need high accuracy data as that my help me. what I understood from your reply that by selecting this option, the extracted value will be more accurate but the problem that it may takes long time, is that right?. the second question is, does i need to do reprojection to C2rcc or it different from area to area.

Thank you in advance

  1. Yes, the calcualtion can take longer
  2. A reprojection is not necessary to improve the results.

Thank you so much for all support, appreciate that.