After loading the InSAR_Input Reference Data image and then the InSAR_Input Match Data image, the images are switched from their locations. Is this is correct?
IMAGINE InSAR has built-in checks that determine whether the geometry is optimal in order to generate the DEM. One of those checks determines if the sensor that captured the Reference image is closest to the actual imaged area. This must be the case, or IMAGINE InSAR switches the images.
You will get a warning message informing you that the geometry of the images you selected is not optimal. Click OK in the warning message so that the images are assigned the correct Reference and Match designations. The images are switched in the Input dialog.