Sentinel 1 classification (novice user)

Hello STEP Forum,

I am an extremely novice user - this is my first post here, although I’ve been reading a lot of the questions and answers here for a while now, but I have a question on the analysis of S1 imagery that I can’t seem to find an answer to, despite watching youtube tutorials and tutorials from ESA.

I am trying to conduct some supervised classification on a Norwegian fjord, and want to generate training samples from 18 different scenes before applying them to 9 new scenes (see image below). Is it possible to combine the samples from the 18 different scenes into 1 vector container? For example, can I combine the ‘ice’ training samples from all 18 scenes into 1 vector container?

Many thanks for any guidance you can offer,