you have to be careful about those values:
This document only assesses the accuracy of your classififer, that means how suitable it was to predict the training data. For example, how many of the sample data fit into the scheme which was built up by the Random Forest.
As you say, this does not mean the classification is correct in terms of actual landcover. As no information on validation is available in SNAP you cannot make predictions on how good the results actually are. For that, you would need to have samples showing the real landcover and validate your results based on them. With that statistics you can also calculate kappa. As far as I know, this is not possible in SNAP yet.
2 Likes