How to do geometric correction in sentinel 3A SLSTR using SNAP

how to do geometric correction in sentinel 3A SLSTR using SNAP

Step need for getting L1- L3 using snap

Geometric correction
Atmospheric correction

If you enable the per-pixel geo-coding in the options, the data is already orthorectified.
image
So, there is no need for an addition geometric correction.

An atmospheric correction for SLSTR is not available in SNAP.

Thank you for your reply…I know SST direct product are available but I want to get SST from L1 data, for that what are the step need to do by SNAP, if cannot suggest some procedure to get sst

You can use the ARC SST processor.
image

If you want to use your own algorithm it depends on the complexity.
It could be possible to use the Band Maths, or you need to implement it in Java or Python.
How to create a new operator - SNAP - Confluence (atlassian.net)

I did resampled , and loaded into Arc SST processor then I load RGB but image look like this

Also may I know one thing , It is possible to get SLSTR L1 data for ocean or Coastal side. I tried to find data but There is only SL1RBT if I am not wrong (this image for land ) can you please how to download that data.

Thank you

For L1 there is no separation in Land and Water. Only for L2.
User Guides - Sentinel-3 SLSTR - Product Types - Sentinel Online - Sentinel Online (esa.int)
You can only download data for your defined region, either on land or water.

The output is not intended to be used directly in an RGB.
If you open for example the N2 band you get a view like this:


Then you can select a colour palette in the colour manipulation window:

Then the view looks like this: