SLSTR_L1 flipping

I have noticed that SLSTR_L1 night acquisitions are flipped of 180 degrees. When syncronizing veiws between OLCI_L1 radiance composite and any SLSTR_L1 band, it is noticeable this “geographical flip”…
Note below on Portugal costline:

This happens only in night acquisitions, not for day acquisitions…Why is this the case? Is it due to satellite acquisition settings? or to some wrong geographical projections of SLSTR products? Or maybe to some software visualization issues?

This is indeed because of the orbit. SNAP displays the SLSTR data as it is provided. A Flip operator is available via gpt on the command line and in the GraphBuilder. It can be used to flip the data.

Is there a recommended procedure for co-locating with S-2 for example?

If you collocate the geo-locations are used as the reference. So, the SLTR would be flipped automatically.

Good to know…Just tested and it works fine!
Thank you for fast reaction !