Scale for zoomed scene

SNAP gives Scale for whole Scene. But i need the Scale of that Particular Area of Interest(AOI) i.e. zoomed image . Is there any possibility i can fix that scale ??

You could create s subset of the scene. Use context menu of the view image and select “Spatial Subset from View”.
But I created an entry (SITBX-502) in our issue database, that the scale should stay within the view bounds when zooming.