Classes in Maximum likelihood classification

Microwave Toolbox
#1

Hello everybody!
I am trying to perform a supervised classification of the type maximum likelihood classification of an image obtained from Sentinel-1.
I have analyzed how various types of vegetation have changed over the years. For this I have made several data vector polygons for each type of vegetation. What I would like to do is tell the classifier that Class 1 is the one represented by the training vectors Pol_1, Pol_2 and Pol_3; that class 2 is the one represented by the training vectors Pal_1, Pal_2 and Pal_3.
Would anyone know how to do that?

Thank you very much in advance

#2

Did you digitize the polygons in SNAP or outside?

You can digitize multiple polygons belonging to one class as described in this tutorial: Landcover classification with Sentinel-1 GRD (pages 21-22)

If you collected them outside SNAP, you can use a dissolve tool to merge them into one multi-polygon per class.

But you can also re-classify the results and assign one pixel value to Pol1-3 and Pal1-3.