Basically the processing chain of SLC radarsat (interferometric processing) should be as below,
You have two SLC’s Radarsat images,
Open a pair of SLC products --------> Use BanSelect to select (polarization) -------->Apply InSAR Optimized Corregistration-------->Generate interferogram and coherence-------->Apply Topographic Phase Removal-------->Apply Goldstein Phase Filtering-------->Export to Snaphu and unwrapping-------->import from snaphu-------->Apply phase to displacement